Stretch marks are narrow streaks or lines that occur on the surface of the skin.
Doctors often refer to stretch marks as stria, striae or – during pregnancy – striae gravidarum.
The tummy (abdomen), buttocks, breasts and thighs are the areas of the body most often affected.
Stretch marks are often red or purple to start with, before gradually fading to a silvery-white colour. They're usually long and thin.
What causes stretch marks?
Stretch marks are the result of the skin suddenly stretching. The middle layer of skin (dermis) breaks in places, allowing the deeper layers to show through.
The dermis can be stretched:
as a result of weight gain
due to growth spurts during puberty
When to see your GP
See your GP if you have stretch marks that don't seem to be linked to weight gain or growth, because they may be due to another condition.
In rare cases, stretch marks are caused by syndromes such asCushing’s syndrome or Marfan syndrome, or from the overuse of powerful steroid creams or ointments on the skin.
Treating stretch marks
Most stretch marks aren't particularly noticeable and will fade over time.
If you have unsightly stretch marks, or if they affect a large area of your body, you may want to try one of the treatment options available.
Creams, gels, lotions, laser surgery and cosmetic surgery are all used to treat stretch marks. However, there's little medical evidence to show that these treatments are particularly effective, so it's important to be realistic about what they can achieve.
It should also be noted that laser treatment and cosmetic surgery for stretch marks aren't available on the , and private treatment can be expensive.
Preventing stretch marks
In certain situations, such as during pregnancy, it isn't possible to prevent stretch marks.
However, maintaining a healthy weight and looking after your skin can reduce your risk of getting them.
Stretch marks that develop during pregnancy are known as striae gravidarum
Who gets stretch marks?
Stretch marks are very common. Anyone can get them, but they tend to affect women more than men.
About 8 out of 10 women get stretch marks during pregnancy. About 7 out of 10 girls and 4 out of 10 boys get them during puberty.
Look after your skin
Benefit your skin by stopping smoking, plus how to protect your skin against sun damage and more
Symptoms of stretch marks
Not everyone gets stretch marks – it depends on your skin type.
Collagen is a protein in your skin, which keeps it elastic and stretchy. Having a lot of collagen in your skin makes it less likely that you'll get stretch marks.
How stretch marks develop
Before the stretch marks appear, the affected skin will become thin, flattened and pink, and may feel itchy.
The stretch marks themselves then appear as red or purple streaks or lines, but can be pink, reddish-brown or dark brown, depending on your skin colour.
They can occur in patches of parallel lines on your body and often appear "scar-like".
To start with, the lines will be slightly raised and may feel wrinkly, before eventually flattening out.
As the lines become flatter, they will begin to fade and change to a white or silvery colour.
Stretch marks usually fade and become less noticeable over time, but this can sometimes take years.
Where stretch marks occur
Stretch marks can occur anywhere where the skin has been stretched.
They usually – but not always – develop on areas where fat is stored, and can occur on your:
shoulders (in bodybuilders)
Stretch marks can also sometimes occur on the back, where they overlie the spine horizontally (rather like the rungs on a ladder), particularly teenage boys.
Stretch marks that are caused by Cushing’s syndrome (where a person has high levels of a hormone called cortisol in their blood) tend to be wider and larger, and can also appear on the face.
Causes of stretch marks
Stretch marks are the result of rapid stretching of the skin due to sudden growth or weight gain.
This stretching causes the middle layer of skin (the dermis) to tear, allowing the deeper skin layers to show through, forming stretch marks.
The dermis contains strong, inter-connected fibres that allow your skin to stretch as your body grows. However, rapid growth can over-stretch and break the fibres.
The tears in the dermis allow the blood vessels below to show through. This is why stretch marks are often red or purple when they first appear.
When the blood vessels eventually contract, the pale-coloured fat underneath your skin will be visible, and your stretch marks will change to a silvery-white colour.
When stretch marks occur
Stretch marks often occur:
after rapid weight gain
if you have a family history of stretch marks
if you have an underlying health condition or a syndrome, such asMarfan syndrome
after the prolonged or inappropriate use of corticosteroid medication
These are discussed in more detail below.
Stretch marks are common during the later stages of pregnancy, affecting about 8 out of 10 pregnant women. Whether or not you'll get stretch marks depends on your skin type and how elastic it is.
During pregnancy, your body produces hormones that soften the ligaments in your pelvis so they're more flexible when you give birth. Ligaments are strong bands of tissue that connect joints. However, the hormones also soften the fibres in your skin, making you prone to stretch marks.
As your baby grows, you may get stretch marks on your tummy, as your skin stretches. You may also develop stretch marks on your thighs and breasts as they get bigger.
After childbirth, stretch marks usually fade and become less noticeable, but they don't always disappear completely.
Rapid weight gain
You may get stretch marks if you put on a lot of weight over a short period of time.
The stretch marks sometimes remain even after losing weight, but should eventually fade.
If you diet regularly, stretch marks can occur as your weight goes up and down. Should you need to lose weight, lose it slowly and steadily so that your skin isn't put under strain.
Bodybuilders and athletes can also get stretch marks as their muscles increase in size.
During puberty, the body often develops very quickly in growth spurts.
Boys may get stretch marks on their shoulders and back, and girls may get them on their hips, thighs and breasts.
If you have a close relative with stretch marks, such as your mother, you're more likely to develop them yourself.
Although stretch marks can affect both male and female members of your family, they're most common in women.
Underlying health conditions
Stretch marks can sometimes be caused by rare, underlying health conditions or syndromes, such as Cushing's syndrome and Marfan syndrome.
Cushing's syndrome occurs when the body overproduces the hormone cortisol, which is thought to cause stretch marks to develop.
Marfan syndrome is caused by a faulty gene that affects your body's skin and connective tissues. It weakens your body's tissues, reducing their elasticity (ability to stretch). This means your skin isn't as resistant to stretch marks as it should be.
If you have Marfan syndrome, you may develop stretch marks on your shoulders, hips or lower back.
In rare cases, stretch marks can develop after prolonged or inappropriate use of corticosteroid medicines, such as creams or lotions used to treat skin conditions, including eczema.
Corticosteroids work in a similar way to the hormone cortisol, which is naturally produced by your body.
Corticosteroids can help ease inflammatory skin conditions; however, like cortisol, they can also decrease the amount of collagen in your skin.
Collagen is a protein that helps to keep your skin stretchy. This means that the less collagen there is in your skin, the more likely you are to develop stretch marks.
When using a corticosteroid cream or lotion, make sure you follow the manufacturer's instructions about how and where to apply it. The face, groin and armpits are particularly sensitive areas. If you're unsure, ask your GP or pharmacist for advice.
Treating stretch marks
Stretch marks often aren't noticeable and usually fade over time.
If you have stretch marks that affect a large area of your body, or if you're worried they look unsightly, there are a few treatment options available.
However, there isn't much medical evidence to show that these treatments work.
Cosmetic camouflage (make-up) is available over-the-counter at pharmacies and can be used for small areas of skin affected by stretch marks. Some types are waterproof and can stay in place for two to three days.
Creams, gels and lotions
The manufacturers of creams, gels and lotions often claim that they can remove stretch marks.
These products are essentially skin moisturisers and are available from pharmacies, supermarkets, and health and beauty shops.
It's recommended that you apply these products when your stretch marks are still red or purple. However, it's unlikely that these treatments can prevent stretch marks occurring, or make them fade any more significantly than they will with time alone.
Laser therapy can't completely remove stretch marks, but it may help fade them and make them less noticeable.
Several different types of laser therapy are used to treat stretch marks.
Pulsed dye laser treatment is one type of laser treatment available. It's painless and can be used at an early stage, while your stretch marks are still red or purple.
The energy from the laser is absorbed by the blood vessels underneath your stretch marks. The blood vessels collapse and the red or purple colour either disappears completely or turns white.
Laser therapy for stretch marks isn't available on the and is usually expensive. You will probably need a few treatments to obtain visible results. The exact number will depend on your skin colour and type.
Cosmetic surgery for stretch marks is expensive and rarely recommended.
If you have stretch marks on your tummy (abdomen) and a large amount of loose skin, it may be possible to have an operation known as an abdominoplasty or tummy tuck.
The procedure removes excess fat and skin from your abdomen, and also gets rid of stretch marks below your belly button.
As this type of surgery is carried out for cosmetic reasons (to improve appearance), it isn't available on the . It also carries a number of associated risks and can cause considerable scarring.
Preventing stretch marks
Stretch marks are very common and can't always be prevented.
However, the following advice may help reduce your risk of developing stretch marks.
Gaining weight rapidly over a short period of time is one of the most common causes of stretch marks.
Dieting that results in your weight quickly going up and down – so-called "yo-yo dieting" – can cause stretch marks. Therefore, avoiding rapid weight gain and weight loss can help prevent stretch marks occurring.
If you need to lose weight, you should do it slowly by eating a healthy, balanced diet and exercising regularly. You shouldn't lose more than 0.5kg (1lb) a week.
It's important to eat a healthy, balanced diet that's rich in vitamins and minerals, particularly vitamin E, vitamin C, and the minerals zinc and silicon. These vitamins and minerals will help keep your skin healthy.
A balanced diet will provide all the vitamins and minerals that the body needs. Dietary supplements aren't needed to prevent stretch marks developing.
Stretch marks that occur during pregnancy (striae gravidarum) are usually due to hormonal changes that affect your skin. Gaining pregnancy weight steadily may help minimise the effect of stretch marks.
During pregnancy it's normal for a woman to put on weight over a relatively short period of time. However, it's a myth that you need to "eat for two", even if you're expecting twins or triplets.
You don't need to go on a special diet if you're pregnant, but you should eat a variety of foods every day to get the right balance of nutrients for you and your baby. Your diet should be rich in wholewheat carbohydrates, such as bread and pasta, as well as fruit and vegetables.
During pregnancy, your weight gain should be slow and gradual. The amount of weight you put on will depend on the weight you were before you became pregnant. It's normal to gain 1-2kg (2.2-4.4lb) over the first 12 weeks of your pregnancy.
As a rough guide, during pregnancy, women who are:
underweight (have a BMI of less than 18.5) should gain 12.7-18.1kg (28-40lb)
a normal weight (have a BMI of 18.5-24.9) should gain 11.3-15.9kg (25-35lb)
overweight (have a BMI of more than 25) should gain 6.8-11.3kg (15-25lb)
obese (have a BMI of more than 30) should gain 5-9.1kg (11-20lb).
Speak to your GP, midwife or health visitor if you're worried about not gaining weight at a healthy rate, or if you're concerned about your stretch marks.
Are you overweight?
Body mass index (BMI) is a measure most people can use to check whether their weight is healthy in relation to their height and build.
For most adults, an ideal BMI score is 18.5-24.9.