Sunburn is caused by overexposure to sunlight, which contains ultraviolet radiation (UV rays).

Ultraviolet rays

The sun produces three different types of UV rays. They are:

• UVA rays – these are less potent than UVB rays, but penetrate deeper into the skin. They damage the middle layer (dermis), which contains tissues that give the skin its elasticity. Prolonged exposure to UVA rays can age the skin prematurely.  
• UVB rays – these UV rays are absorbed by the top layer of skin (epidermis). The epidermis releases chemicals that cause the pain, swelling and redness associated with sunburn. 
• UVC rays – are filtered by the earth’s atmosphere, which means that protection against this type of radiation is not required.

UVA and UVB are the two types of ultraviolet rays that cause sunburn.

Sunburn can also be caused by exposure to other sources of UV light, such as tanning beds and phototherapy lamps. These lamps are often used in light therapy to treat conditions such as jaundice in newborn babies (yellowing of the skin).

Exposure to UVA and UVB rays increases your risk of developing skin cancer. Sunburn is a warning sign that you are putting yourself at risk and damaging your skin.

Who’s at risk of sunburn?

Everyone who is exposed to UV light is at risk of getting sunburn. However, the less melanin you have, the less protected you are against the effects of UV light.

You are more likely to get sunburn if you:

• are in a country that is close to the equator, such as Ecuador in South America or Uganda in Africa
• are under six or over 60 years of age 
• have pale, white skin and blonde or red hair 
• are at a high altitude – for example, climbing or skiing
• spend prolonged periods of time outdoors in a sunny climate, particularly when there are clear skies
• are near snow, ice or water where the sun’s rays can reflect onto your skin

Young children and babies are more sensitive to the effects of UV rays.

Melanin

Melanin is a pigment that is produced when your skin is exposed to sunlight. It absorbs the UV radiation found in sunlight to help protect your skin. This results in your skin becoming darker, which is a sign that it has been damaged by UV rays.

If you have fair skin or red hair, or if you have not been in the sun much, your melanin levels will be low. This increases your risk of burning more quickly. Melanin stops you burning so easily, but it does not prevent the other harmful effects of UV radiation.

Sunburn is skin damage caused by ultraviolet (UV) rays. Too much exposure to UV light can make your skin red and painful, which can later lead to peeling or blistering.

The severity of sunburn can vary depending on your skin type and how long you are exposed to UV rays.

However, the main symptoms of sunburn are red, sore and blistering skin. The symptoms may not occur immediately and can take up to five hours to appear.

Read more about the symptoms of sunburn.

UV light

Sources of UV light include:

• sunlight
• tanning beds
• phototherapy lamps – these are used in light therapy to treat conditions such as jaundice in newborn babies (yellowing of the skin)

Sunburn often occurs when the sun’s rays are most intense (usually between 11am and 3pm). However, there is also a risk of getting burned by the sun in other weather conditions.

For example, light reflecting off snow can also cause sunburn. A cloudy sky or breeze may make you feel cooler, but sunlight can still get through and damage your skin.

Who is at risk of sunburn?

Everyone who is exposed to UV light is at risk of getting sunburn. However, the less melanin you have, the less protected you are against the effects of UV light.

Melanin is a pigment that is produced when your skin is exposed to sunlight. It absorbs the UV radiation found in sunlight to help protect your skin. This results in your skin becoming darker, which is a sign that it has been damaged by UV rays.

If you have fair skin or red hair, or if you have not been in the sun much, your melanin levels will be low, increasing your risk of burning more quickly.

Read more about the causes of sunburn.

Melanin stops you burning so easily, but it does not prevent the other harmful effects of UV radiation.

Babies and young children are particularly at risk from sunburn.

Treating sunburn

Treatment for sunburn aims to cool the skin and relieve any pain or symptoms. Applying a cold flannel over the area will help cool the skin, while moisturising lotions and creams will help keep it moist.

Moisturisers that contain aloe vera will help to soothe your skin and calamine lotion can relieve any itching or soreness.

In severe cases of sunburn, you should ask your pharmacist for advice as you may need special treatment from your GP.

You should see your GP if you have sunburn and you feel faint, dehydrated or have severe blistering, or if a young child or baby has sunburn.

Read more about treating sunburn.

Risks of UV rays

Mild sunburn usually gets better between four and seven days after your skin has been exposed to UV rays.

However, damage from sunburn can have long-term effects, and frequent exposure to UV rays for long periods of time increases your risk of developing skin problems, such as skin cancer and premature ageing.

Read more about the risks of long-term exposure to UV rays.

Preventing sunburn

You can reduce your risk of developing skin cancer by protecting your skin with sunscreen. Follow the advice listed below.

• Avoid strong sunlight whenever possible, particularly when the sun is strongest, and cover up with loose clothing and a hat.
• When buying sunscreen, choose one with a sun protection factor (SPF) of at least factor 15 – the higher the better – that protects against both UVA and UVB rays.
• Apply a generous amount of sunscreen at least 15 minutes before going out in the sun and reapply regularly at least every two to three hours. Even water-resistant sunscreens should be reapplied after you come out of the water.
• A stick application with a high SPF is useful for exposed areas, such as your nose, ears and lips. These areas tend to burn more easily.
• Keep babies and young children out of direct sunlight.

Read more about sun safety and protecting your skin.

Seek advice from your GP immediately if you notice changes to any of your moles, such as a change in their size, colour or texture.

There are a number of risks associated with prolonged exposure to ultraviolet (UV) rays.

The risks include:

• premature ageing of the skin and wrinkling (caused by UVA rays)
• solar keratoses – rough, scaly spots on the skin 
• infection – severe blistering from sunburn can cause infection if bacteria gets into breaks in the skin
• photokeratitis, or snow blindness – prolonged exposure to intense sunlight can cause the eyes to become painfully sensitive, but it can be prevented by wearing sunglasses or goggles with UV filters
• skin cancer – people who have been exposed to a lot of ultraviolet light have a higher risk of developing both melanoma and non-melanoma skin cancer

Skin cancer

Exposure to UV rays increases your chances of developing skin cancer. Each year, more than 70,000 cases of skin cancer are diagnosed in the UK. Sun exposure is thought to be responsible for most cases.

Certain people are more at risk of developing skin cancer as a result of prolonged exposure to the sun. People with an increased risk are: 

• those with very fair skin that burns easily
• those who have had several cases of sunburn during childhood
• those with a family history of skin cancer
• those with lots of moles on their body (more than 50)
• those who are being treated with immunosuppressant medication

You can reduce your risk of developing skin cancer by protecting your skin with sunscreen.

Read more about protecting your skin and sun safety in general.

The symptoms of sunburn vary from person to person, and depend on your skin type and the length of time you are exposed to UV rays.

The paler your skin, the more likely you are to burn compared with someone with darker skin.

The symptoms of sunburn include:

• red, sore skin (erythema) 
• skin that is warm and tender to the touch
• flaking and peeling skin after a number of days (usually four to seven days after exposure)

Dark skin can also burn and become damaged if exposed to enough UV light. However, as dark skin contains more melanin (pigment), it can tolerate sunlight without burning for longer than paler skin.

The symptoms of sunburn are not always immediately obvious. They usually begin three to five hours after exposure to the sun’s rays, and are usually at their worst 12 to 24 hours after being in the sun.

Severe sunburn

Severe cases of sunburn can cause:

• blistering
• swelling of the skin (oedema)
• chills
• a high temperature (fever) of 38ºC (100.4ºF) or above
• a general feeling of discomfort (malaise)

You may also have symptoms of heat exhaustion, such as:

• dizziness
• headache
• nausea (feeling sick)

Read more about heat exhaustion and heatstroke.

You should contact your GP surgery if you have severe symptoms of sunburn, if you are burnt over a large area, or if a young child or baby has sunburn.

If you have sunburn, you should avoid direct sunlight by covering up the affected areas of skin and staying in the shade until your sunburn has healed.

However, protecting your skin from the sun using sunscreen is better than treating it.

Read more about sun protection for your eyes and skin, including advice about sunscreen and how to apply it.

Most cases of sunburn can be treated at home by following the advice below.

Water

Cool the skin by sponging it with lukewarm water or by having a cool shower or bath. Applying a cold compress such as a cold flannel to the affected area will also cool your skin.

Drinking plenty of fluids will help to cool you down and will replace water lost through sweating. It will also help prevent dehydration (when the normal water content in your body is reduced, causing thirst and light-headedness). You should avoid drinking alcohol as it will dehydrate you even more.

Moisturiser

For mild sunburn, apply a moisturising lotion or aftersun cream, available at pharmacies. Aftersun cream will cool your skin and moisturise it, helping to relieve the feeling of tightness.

Moisturisers that contain aloe vera will also help soothe your skin. Calamine lotion can relieve any itching or soreness.

Painkillers

Painkillers can help relieve the pain and reduce the inflammation caused by sunburn.

Paracetamol can be used to treat pain and control fever. Ibuprofen is a type of non-steroidal anti-inflammatory drug (NSAID) that can help relieve pain, reduce inflammation and lower a high temperature.

Aspirin should not be given to children who are under the age of 16. 

Severe sunburn

Severe cases of sunburn may require special burn cream and burn dressings. Ask your pharmacist for advice. You may need to have your burns dressed by a nurse at your GP surgery.

Very severe sunburn cases may require treatment at your local accident and emergency (A&E) department.