Sun protection is about more than avoiding sunburn. Ultraviolet (UV) radiation can damage skin cells, contribute to premature skin aging, worsen some pigmentation disorders, and increase the risk of skin cancer over time.

Sunscreen is one part of a complete sun-protection strategy. Shade, protective clothing, hats, sunglasses, and avoiding intense UV exposure are also important.

For most people who need sunscreen, dermatology organizations recommend choosing a product that provides broad-spectrum protection, SPF 30 or higher, and water resistance, particularly when spending time outdoors.

The right sunscreen, however, is not simply the one with the highest SPF or the most expensive ingredients. A sunscreen is useful only when it is applied adequately and used consistently enough for your situation.

Quick answer: What sunscreen should you use?

For routine sun protection, look for a sunscreen that provides:

Broad-spectrum protection, covering both UVA and UVB radiation
SPF 30 or higher
Water resistance if you will sweat, swim, or spend significant time outdoors
A formulation that you are comfortable applying generously and reapplying

Apply sunscreen to exposed skin before going outdoors. Use enough to adequately cover the skin, and reapply approximately every two hours while outdoors, or sooner after swimming, sweating, or towel drying.

Sunscreen should complement, not replace, shade and protective clothing.

For people concerned about melasma or dark spots, a tinted sunscreen containing iron oxides can provide additional protection against visible light, which can worsen hyperpigmentation, particularly in darker skin tones.

What is sunscreen?

Sunscreen is a topical product designed to reduce the amount of ultraviolet radiation reaching the skin.

Sunscreens contain active ingredients that absorb, scatter, or otherwise attenuate UV radiation. Depending on the formulation, sunscreen may contain mineral ingredients such as zinc oxide or titanium dioxide, organic UV filters, or a combination of different filters.

Sunscreen does not create an invisible force field around the body. Its effectiveness depends on factors including:

The type and amount of sunscreen used
Whether it provides broad-spectrum protection
Its SPF rating
Whether it is water resistant
How evenly it is applied
Whether it is reapplied appropriately
How much UV exposure occurs
Whether other protective measures are used

This is why sunscreen works best as part of a broader sun-protection routine.

Why does sun protection matter?

Sunlight contains ultraviolet radiation that can damage skin.

The two types of UV radiation most relevant to everyday sunscreen use are UVA and UVB.

Repeated or excessive UV exposure can contribute to:

Sunburn
DNA damage in skin cells
Premature skin aging
Uneven pigmentation
Some photosensitivity reactions
Skin cancers, including melanoma and non-melanoma skin cancers

The World Health Organization identifies UV radiation as a major cause of skin cancer and recommends combining sunscreen with shade, protective clothing, hats, and other measures to reduce excessive UV exposure.

Sun protection is relevant to people of all skin tones. People with darker skin generally have a lower risk of many UV-related skin cancers than people with lighter skin, but they can still develop skin cancer. UV and visible light can also contribute to hyperpigmentation in darker skin.

UVA vs. UVB: What is the difference?

Understanding UVA and UVB helps explain why broad-spectrum sunscreen matters.

Feature	UVA	UVB
Main association	Skin aging and pigmentation	Sunburn
Penetration	Penetrates deeper into skin	More concentrated in superficial skin
Role in skin cancer	Contributes to skin cancer risk	Strongly associated with DNA damage and skin cancer
Through ordinary window glass	Much of UVA can pass through	Most UVB is blocked
Sunscreen label	Included under broad-spectrum protection	Reflected partly by SPF

These descriptions are simplified because both UVA and UVB can contribute to skin damage and skin cancer.

What is UVA?

UVA radiation has longer wavelengths than UVB and penetrates deeper into the skin.

It contributes to:

Premature skin aging
Pigmentation
DNA damage
Skin cancer risk

UVA can also pass through ordinary window glass to a substantial degree.

What is UVB?

UVB has shorter wavelengths and is strongly associated with sunburn.

It can also damage DNA and contribute to skin cancer.

UVB exposure varies with factors such as geographic location, season, time of day, altitude, and atmospheric conditions.

Because UVA and UVB have different properties, SPF alone does not describe complete UV protection.

What does SPF mean?

SPF stands for Sun Protection Factor.

SPF primarily measures how well a sunscreen protects skin against UV radiation that causes sunburn, particularly UVB.

The American Academy of Dermatology recommends using sunscreen with an SPF of 30 or higher.

SPF should not be interpreted as the number of hours you can safely stay in the sun.

For example, SPF 30 does not mean you can remain outdoors 30 times longer than you could without sunscreen.

SPF testing is performed under controlled conditions using a specified amount of sunscreen. Most people apply less than the amount used in standardized testing, which can reduce the actual protection they receive.

Is SPF 30 enough?

SPF 30 provides substantial protection against UVB when applied correctly.

The AAD notes that SPF 30 filters approximately 97% of UVB radiation under testing conditions.

Higher SPF values provide additional protection, but no sunscreen blocks 100% of UVB.

The practical difference between SPF 30 and higher SPF products is smaller than many consumers assume.

More importantly, applying enough sunscreen and reapplying it appropriately matter greatly.

A person using SPF 100 very sparingly may receive less protection than someone who applies SPF 30 adequately.

What does broad-spectrum sunscreen mean?

Broad-spectrum sunscreen protects against both UVA and UVB radiation.

This is important because SPF primarily communicates protection against sunburn-producing UV radiation and does not by itself describe the full range of UVA protection.

When choosing sunscreen, look for:

Broad spectrum + SPF 30 or higher

This combination is a practical baseline for routine sun protection.

What does water-resistant sunscreen mean?

There is no sunscreen that is completely “waterproof.”

Instead, some products are tested and labeled water resistant.

Under U.S. FDA labeling rules, water resistance is designated for either:

40 minutes, or
80 minutes

depending on the product’s test results.

Water resistance does not mean the sunscreen remains fully effective indefinitely while swimming.

You should reapply after swimming, sweating heavily, or towel drying, even when using a water-resistant product.

Mineral vs. chemical sunscreen

You may see sunscreen described as:

Mineral
Chemical
Organic
Physical
Hybrid

These terms can be confusing.

What is mineral sunscreen?

Mineral sunscreens generally use zinc oxide, titanium dioxide, or both as active UV filters.

They are sometimes called physical sunscreens.

Mineral formulations can be useful for people with sensitive skin, although individual products vary.

One disadvantage is that some formulations can leave a noticeable white or gray cast, particularly on darker skin tones. Newer formulations and tinted products can reduce this problem.

What is chemical sunscreen?

“Chemical sunscreen” is a commonly used consumer term for sunscreens that use organic UV filters rather than zinc oxide or titanium dioxide as their primary active ingredients.

These filters absorb UV radiation.

Some sunscreens contain multiple organic filters to provide broad-spectrum protection.

Which is better?

There is no universal winner.

A sunscreen can provide effective protection regardless of whether its formulation is mineral, organic-filter, or hybrid, provided it offers appropriate broad-spectrum protection and is used correctly.

The most useful sunscreen is one that provides appropriate protection and that you can comfortably use in sufficient amounts.

Sunscreen for different skin types

Sunscreen for oily skin

If your skin becomes oily easily, look for formulations described as:

Lightweight
Gel
Fluid
Oil-free
Non-comedogenic

“Non-comedogenic” means the formulation is designed to be less likely to clog pores.

This does not guarantee that a product will never cause breakouts because individual skin responses vary.

Sunscreen for dry skin

People with dry skin may prefer a sunscreen with moisturizing ingredients or a cream or lotion texture.

If your skin is very dry, applying moisturizer underneath sunscreen may improve comfort.

Some sunscreens combine moisturizing and sun-protection functions.

Sunscreen for sensitive skin

If your skin is sensitive, consider a simple, fragrance-free formulation.

Mineral sunscreens containing zinc oxide or titanium dioxide are often suggested for sensitive skin because they may be less irritating for some people.

However, sensitivity is individual. Any sunscreen can potentially cause irritation or allergic contact dermatitis in a susceptible person.

Sunscreen for acne-prone skin

Acne-prone skin does not mean you should avoid sunscreen.

Look for a sunscreen that is:

Non-comedogenic
Comfortable on oily skin
Lightweight if preferred
Broad spectrum
SPF 30 or higher

Some acne treatments can make skin more sensitive or irritated, making sun protection particularly useful.

If a sunscreen consistently causes breakouts or irritation, try a different formulation rather than abandoning sun protection altogether.

Sunscreen for darker skin tones

People with brown or Black skin still benefit from sun protection.

Melanin provides some natural protection against UV radiation, but it does not eliminate the risk of skin cancer or other effects of UV exposure.

For darker skin tones, visible light can also contribute to hyperpigmentation.

This is particularly relevant for conditions such as:

Melasma
Post-inflammatory hyperpigmentation
Other dark spots and patches

For people concerned about pigmentation, a tinted sunscreen containing iron oxides may provide additional protection against visible light.

The American Academy of Dermatology recommends looking for a tinted product that also provides broad-spectrum protection, SPF 30 or higher, and water resistance.

Sunscreen for melasma

Sun and visible light can worsen melasma.

If you have melasma, sun protection is an important part of management.

A dermatologist may recommend:

Broad-spectrum SPF 30 or higher
Water-resistant sunscreen
Regular application
Shade
Protective clothing
A wide-brimmed hat
Tinted sunscreen containing iron oxides

Tinted sunscreen is particularly relevant because iron oxides can provide protection against some visible light.

Sunscreen does not cure melasma by itself. Persistent melasma may require additional treatment prescribed or recommended by a dermatologist.

Sunscreen for hyperpigmentation and dark spots

Sun exposure can make some dark spots more persistent.

Visible light may also contribute to hyperpigmentation, particularly in darker skin tones.

Consistent sun protection can help reduce additional darkening while other treatments are used.

For pigmentation concerns, consider a tinted broad-spectrum sunscreen containing iron oxides.

However, not every dark spot is simply sun-related. A new, changing, bleeding, or unusual pigmented lesion should be evaluated rather than assuming it is ordinary hyperpigmentation.

How much sunscreen should you apply?

Using too little sunscreen can substantially reduce the protection suggested by the product’s SPF rating.

For full-body application in an average adult, the AAD commonly uses approximately 1 ounce, roughly enough to fill a shot glass, as a practical amount.

For the face, neck, and other exposed areas, the exact amount varies with the size of the area and the product.

One practical approach for the face is to apply enough to provide an even layer without leaving large areas uncovered.

Some dermatology guidance uses the “two-finger” approach for face application, but this is only a practical estimate. Different products have different textures and packaging, so the important principle is adequate, even coverage.

If you are unsure, follow the manufacturer’s application instructions.

Where should you apply sunscreen?

Apply sunscreen to all exposed skin that will not be covered by protective clothing.

Commonly missed areas include:

Ears
Back of the neck
Hairline
Nose
Lips
Eyelids and around the eyes, using an appropriate product and avoiding direct contact with the eyes
Tops of the feet
Hands
Forehead
Scalp in areas where hair is thinning

Do not forget exposed areas simply because they are small.

When should you apply sunscreen?

Apply sunscreen before going outdoors.

The AAD recommends applying sunscreen approximately 15 minutes before sun exposure.

This gives the product time to form an effective protective layer according to its formulation.

If you apply sunscreen only after you have already been outside, your skin may have already received UV exposure.

How often should you reapply sunscreen?

When outdoors, reapply approximately every two hours.

Reapply sooner after:

Swimming
Heavy sweating
Towel drying
Activities that remove or rub off the sunscreen

The two-hour rule is not a timer that means sunscreen suddenly becomes completely ineffective at exactly 120 minutes.

Rather, it is practical guidance because sunscreen can be removed, redistributed, or lose effectiveness through exposure to sunlight, water, sweat, and friction.

Do you need sunscreen on cloudy days?

Yes, UV radiation can reach the skin on cloudy days.

Cloud cover can reduce some UV exposure, but it does not eliminate it.

Your actual level of exposure depends on conditions such as location, time of day, season, altitude, cloud cover, and the UV Index.

For everyday decisions, checking the local UV Index can be useful.

The WHO recommends sun-protection measures when the UV Index reaches 3 or above.

Do you need sunscreen in winter?

It depends on your environment and UV exposure.

UV radiation does not disappear simply because the temperature is lower.

People participating in outdoor activities, traveling to high-altitude locations, spending time near reflective surfaces such as snow, or living in areas with substantial UV exposure may need sun protection during winter as well.

A cold day can still produce meaningful UV exposure.

Do you need sunscreen indoors?

Not everyone needs to apply sunscreen simply because they are indoors.

The need depends on exposure.

UVA can pass through ordinary window glass, while most UVB is blocked.

If you spend significant time next to windows receiving direct sunlight, work outdoors intermittently, drive for long periods, or have a condition such as melasma that is aggravated by light, your dermatologist may recommend consistent daytime sun protection.

For many people who remain indoors away from direct sunlight, routine sunscreen use may be less important than when they are outdoors.

Does sunscreen prevent skin cancer?

Sunscreen is an important component of skin-cancer prevention, but it should not be viewed as the only protective measure.

Long-term evidence supports the role of sun protection in reducing UV-related skin damage. A long-term randomized trial included in USPSTF evidence found fewer melanomas among participants assigned to regular sunscreen use compared with those following their usual practices.

At the same time, research on sunscreen and skin cancer is complex, and observational studies can be affected by differences in sun exposure and behavior between sunscreen users and nonusers.

The safest interpretation is that sunscreen should be used as one component of comprehensive UV protection, alongside shade and protective clothing.

Sunscreen should never be treated as permission to spend unlimited time in intense sunlight.

Does sunscreen prevent premature skin aging?

UV exposure is an important contributor to photoaging.

Photoaging refers to visible skin changes caused or accelerated by chronic environmental exposure, particularly UV radiation.

These changes can include:

Wrinkles
Uneven pigmentation
Loss of elasticity
Rougher skin texture
Visible sun damage

Clinical evidence supports sun protection as an important measure for reducing photoaging.

Sunscreen cannot reverse all existing signs of aging, but consistent protection can reduce ongoing UV exposure.

Does sunscreen prevent tanning?

No sunscreen completely prevents tanning.

Tanning occurs when skin responds to UV exposure by increasing pigment production.

A tan is not evidence that the skin has become healthier. UV exposure that produces tanning also represents biological stress and damage to skin cells.

No sunscreen provides 100% protection against UV radiation.

If you want to avoid tanning, combine sunscreen with shade, clothing, hats, and limiting intense sun exposure.

Is there a safe way to tan?

There is no completely safe way to tan through UV exposure.

A tan produced by sunlight or indoor tanning represents a response to UV radiation.

Indoor tanning devices can expose the skin to carcinogenic UV radiation and increase skin cancer risk.

If you want a tanned appearance without UV exposure, cosmetic self-tanning products are an alternative because they do not require UV radiation to produce the appearance of a tan.

However, self-tanning products generally should not be considered substitutes for sunscreen.

Sunscreen and vitamin D

Vitamin D is important for bone health and other physiological functions.

Some people worry that sunscreen could prevent the body from making enough vitamin D.

Available evidence has not established that routine sunscreen use causes vitamin D deficiency in typical real-world use.

People who are at risk of vitamin D deficiency should discuss appropriate dietary sources, supplements, or testing with a healthcare professional rather than intentionally seeking unprotected UV exposure.

UV radiation is not a recommended treatment for obtaining vitamin D.

Sunscreen during pregnancy

Sun protection remains important during pregnancy.

Pregnancy can also be associated with changes in pigmentation, including melasma.

People who are pregnant or trying to become pregnant should discuss prescription skin-care treatments and specific active ingredients with their healthcare professional.

For sunscreen itself, the choice may depend on personal preference, skin sensitivity, and medical circumstances.

If you have concerns about particular sunscreen ingredients during pregnancy, discuss the product with your obstetrician or dermatologist rather than avoiding sun protection altogether.

Sunscreen for babies and children

Young children’s skin needs careful protection from UV exposure.

For babies younger than 6 months, the AAD emphasizes shade and protective clothing and recommends avoiding direct sun exposure where possible. If adequate shade and clothing are not available, the AAD notes that a small amount of sunscreen may be used on exposed areas.

For children 6 months and older, the AAD recommends broad-spectrum, water-resistant sunscreen with SPF 30 or higher on exposed skin.

Mineral ingredients such as zinc oxide and titanium dioxide may be less irritating for the sensitive skin of infants and young children.

Children should also use:

Shade
Protective clothing
Wide-brimmed hats
UV-protective sunglasses

Sunscreen should not be treated as a substitute for these measures.

Sunscreen and sensitive skin

Sensitive skin can react to fragrance, preservatives, certain UV filters, or other ingredients.

If your skin burns, stings, becomes red, or develops a rash after sunscreen use:

Stop using the suspected product.
Gently wash the product off if appropriate.
Avoid applying additional irritating products to the area.
Consider a simpler fragrance-free formulation.
Seek medical advice if the reaction is severe or persistent.

A dermatologist can help determine whether the problem is irritation, allergic contact dermatitis, photoallergy, or another skin condition.

Can sunscreen cause acne?

Some sunscreen formulations can contribute to clogged pores or breakouts in susceptible people.

This does not mean sunscreen itself is inherently acne-causing.

If you have acne-prone skin, consider a product labeled non-comedogenic and choose a texture that feels comfortable enough to use consistently.

If one sunscreen causes breakouts, trying another formulation may solve the problem.

Avoid abandoning sun protection altogether because of one product.

Sunscreen and eczema

People with eczema can still use sunscreen.

However, irritated or inflamed skin may react more easily to certain ingredients.

A fragrance-free, gentle formulation may be easier to tolerate.

If sunscreen repeatedly causes burning or rash on eczema-prone skin, a dermatologist can help identify a suitable formulation.

Remember that eczema itself can have multiple triggers, so not every reaction after sunscreen application necessarily means the UV filter is responsible.

Does makeup with SPF replace sunscreen?

Makeup containing SPF can contribute to sun protection, but relying on makeup alone may not provide the same protection as applying an appropriately tested sunscreen in an adequate amount.

People generally apply much less makeup than the standardized amount used when SPF is measured.

If you are spending meaningful time outdoors, use a dedicated broad-spectrum sunscreen and consider SPF makeup as an additional layer rather than your only source of protection.

Can moisturizer with SPF replace sunscreen?

A moisturizer with SPF can be useful if it provides adequate broad-spectrum protection and is applied sufficiently.

The AAD notes that moisturizer with sunscreen can be appropriate.

However, if you will spend significant time outdoors, choose a broad-spectrum, SPF 30 or higher, water-resistant product and apply enough to cover exposed skin.

The distinction is less about whether a product is called “moisturizer” or “sunscreen” and more about its tested protection, formulation, amount used, and how it is applied.

Sunscreen sticks, sprays, lotions, and creams

Different formats can work effectively.

Lotion or cream

These make it relatively easy to see where sunscreen has been applied and can work well for large exposed areas.

Stick

Sunscreen sticks can be convenient for small areas such as the nose, around the eyes, or lips.

However, adequate coverage still matters. Multiple passes may be necessary to achieve an even layer.

Spray

Sprays can be convenient for large body areas.

Avoid inhaling spray sunscreen and do not spray it directly onto the face. Spray it into your hands first when applying to the face.

Be careful around flames because some spray products may be flammable.

Powder sunscreen

Powder products can be convenient for touch-ups, particularly on the scalp or over makeup.

However, coverage can be difficult to judge, and they should not automatically be assumed to provide the same practical protection as a sufficiently applied lotion or cream.

Does sunscreen expire?

Yes.

Sunscreen can lose effectiveness over time.

Check the expiration date on the package.

If there is no expiration date, FDA guidance generally requires products to retain their original strength for at least three years when stored under appropriate conditions, although product-specific requirements can differ.

Avoid storing sunscreen in excessive heat for prolonged periods.

A sunscreen left for long periods in a hot car may degrade more quickly.

Can you use expired sunscreen?

It is better not to rely on expired sunscreen.

If the product has passed its expiration date, replace it.

Sun protection is not the place to gamble with an old product whose effectiveness may have declined.

Common sunscreen mistakes

Using too little

This is one of the most important mistakes.

SPF testing assumes a standardized amount of sunscreen. Applying substantially less can reduce protection.

Forgetting reapplication

Sweating, swimming, towel drying, and friction can remove sunscreen.

Using SPF without broad-spectrum protection

SPF does not tell you the complete UVA protection of a product.

Look for broad-spectrum labeling.

Treating sunscreen as permission to stay in the sun longer

Sunscreen should not be used to intentionally extend time in intense sunlight.

Forgetting the ears and neck

These areas are commonly exposed.

Applying only on sunny days

UV exposure can occur on cloudy days.

Choosing a product you dislike

If a sunscreen feels unpleasant, leaves a cast, irritates your skin, or causes breakouts, you may be less likely to use it consistently.

Finding a formulation you can comfortably use is important.

Assuming darker skin does not need sun protection

Darker skin provides more natural melanin-related protection, but it does not eliminate UV-related skin damage, skin cancer risk, or pigmentation problems.

A simple daily sunscreen routine

A practical routine does not need to be complicated.

Morning

Cleanse if appropriate for your skin.
Apply your usual skin-care products.
Apply broad-spectrum SPF 30 or higher to exposed skin.
Allow sufficient time before going outdoors according to the product instructions.
Add protective clothing, a hat, sunglasses, or shade when appropriate.

During outdoor activities

Reapply approximately every two hours and sooner after swimming, sweating, or towel drying.

Evening

Remove sunscreen, makeup, and other products according to your normal cleansing routine.

Moisturize if needed.

A simple way to choose sunscreen

If you are standing in a store looking at dozens of products, start with the label.

Look for:

1. Broad spectrum

Protects against UVA and UVB.

2. SPF 30 or higher

Provides substantial UVB protection when adequately applied.

3. Water resistant

Especially useful for outdoor activities, sweating, and swimming.

4. Suitable formulation

Choose a texture and ingredient profile appropriate for your skin.

5. Tinted + iron oxide when pigmentation is a concern

This may provide additional visible-light protection, particularly for melasma and hyperpigmentation in darker skin tones.

Sunscreen myths and facts

Myth	Fact
SPF 100 lets you stay outside 100 times longer	SPF is not a time multiplier
SPF 30 blocks all UV	No sunscreen blocks 100% of UVB
Waterproof sunscreen exists	Sunscreens can be water resistant, not completely waterproof
Dark skin does not need sunscreen	Darker skin still experiences UV-related damage and can develop skin cancer
Sunscreen is only needed at the beach	Everyday UV exposure can occur during ordinary outdoor activities
A tan is healthy	A UV-induced tan is a response to skin damage
More sunscreen is always better	Adequate coverage matters; extremely high SPF does not eliminate the need for reapplication
Makeup SPF always replaces sunscreen	The amount of makeup normally applied may not provide the labeled SPF
Sunscreen makes sun exposure completely safe	Sunscreen is only one part of sun protection
Expensive sunscreen is automatically better	Price does not determine effectiveness

When should you see a dermatologist?

Consider professional evaluation if you notice:

A new or changing mole
A spot that repeatedly bleeds
A lesion that does not heal
A rapidly changing pigmented lesion
A persistent scaly or crusted area
Severe or repeated sunburns
Persistent photosensitivity
A rash that appears after sun exposure
Persistent melasma or hyperpigmentation
A sunscreen reaction that does not resolve
Significant skin damage from chronic sun exposure

Sunscreen cannot diagnose or treat an existing skin cancer or unexplained skin lesion.

If a lesion is changing, bleeding, painful, or otherwise concerning, seek appropriate medical assessment rather than simply applying more sunscreen.

What if you get sunburned?

The first step is to get out of the sun.

For a mild sunburn, supportive care can include:

Cool baths or showers
Gentle moisturizing
Drinking enough fluids
Avoiding further UV exposure while the skin heals
Not deliberately peeling or removing damaged skin

Seek medical attention for severe sunburn, particularly when there are extensive blisters, severe pain, dehydration, fever, confusion, fainting, or other concerning symptoms.

Sunburn in children deserves particular attention because severe childhood UV exposure is associated with increased lifetime skin-cancer risk.

The bottom line

Sunscreen is an important tool for reducing exposure to harmful UV radiation, but it works best as part of a complete sun-protection strategy.

For most people, a practical starting point is:

Broad-spectrum + SPF 30 or higher + water resistance when needed + adequate application + regular reapplication.

Combine sunscreen with shade, protective clothing, a wide-brimmed hat, and UV-protective sunglasses when appropriate.

If you have melasma or are prone to hyperpigmentation, consider a tinted sunscreen containing iron oxides, because visible light can contribute to pigmentation, particularly in darker skin tones.

Most importantly, choose a sunscreen you can tolerate and use consistently. The goal is not to find a “perfect” product. The goal is to reduce unnecessary UV exposure while making sun protection a realistic part of everyday life.

Medical disclaimer: This article provides general educational information about sunscreen and sun protection. It does not diagnose or treat an individual medical condition and does not replace advice from a qualified healthcare professional.