As already mentioned, stretch marks are caused by sudden stretching of the dermis layer of skin.
Rapid growth – the dermis is made of tough fibres connected with each other in a way that allows the skin to extend as the body grows. However, if there is a sudden, rapid growth in the body over a brief period of time, the fibres become thin, elongated and stretch-out beyond limit, causing a few of them to break. This fibre breakage in the dermis, thin tears are created so that the blood vessels underneath show through the top layers of skin. This explains why stretch marks are reddish in colour to begin with. Gradually the blood vessels become smaller leaving only fat under the skin to be seen through as a silver-white colour streak in the skin.
Every individual has different susceptibility to getting stretch marks. It depends on the cortisol hormone production in the body, larger the amounts of cortisol lower is the collagen in the skin. Collagen is the protein in the skin which provides elasticity and flexibility. Thus if collagen is less, skin loses its stretch ability and has more tendency to develop stretch marks.
Pregnancy – pregnant women are quite likely to develop stretch marks after the sixth month. Hormones produced by the body during pregnancy help to make the pelvic ligaments softer to ease the delivery. These hormones end up softening the skin fibres as well, thus increasing the tendency to get stretch marks. With the growth of the baby inside, the abdominal skin of the woman gets stretched and develops stretch marks. Breasts and thighs also become heavier and bigger and thus are prone to getting the stretch marks.
Gaining weight rapidly – putting on a good amount of weight too soon, may also be a cause for stretch marks to appear and to stay even if one happens to lose weight. However, the do fade away with time.
One should be careful while exercising or dieting, to lose weight gradually so as not to put strain on the skin.
Athletes and bodybuilders get stretch marks as their muscles build up in size.
Puberty – youngsters grow very fast, in spurts, especially during adolescent years. Men tend to get stretch marks on back and shoulders and women on breasts, thighs and hips.
Family history – one is likely to have stretch marks, if a close relative such as mother has it. Women are more likely to get stretch marks than men.
Certain medications – corticosteroid medicines like tablets, creams or lotions for eczema, work in the same way as cortisol hormone produced in the body. They do ease the skin inflammation and irritation, but end up decreasing the collagen in the skin, hence increasing the likelihood of getting stretch marks.
Certain health conditions such as Cushing’s syndrome and marfan syndrome can be a cause for developing stretch marks.
Cushing’s syndrome – as already explained above, in this condition, body produces larger than normal amounts of cortisol hormone, causing symptoms of weight gain, increased facial and body hair and back ache. The result is occurrence of stretch marks, in this case, they are more noticeable and dark coloured.
Marfan syndrome – this is a genetic disorder affecting the connective tissues, including skin, in the body. The condition adversely affects the strength and flexibility of the tissues. Apart from other symptoms, this disorder reduces skin resistance to stretch marks and these appear on lower back, hips and shoulders.
Stretch marks – 2