Reason behind Stretch Mark?
What is the reason behind stretch mark?
There are many reason for stretchmarks like Pregnancy, Natural growth for adolescent boys and girls, Rapid weight gain/loss, Long term lacking of certain nutrients ,Sudden change in muscle girth or environmental conditions. The most common areas affected by stretch marks are the hips, breasts, buttocks, thighs and abdomen.
One theory is that stretchmark develop when the skin is stretched to the point of breaking down, due to a dramatic increase in the size of tissue. This stretching of the skin is similar to elastic losing its elasticity. The actual stretch marks develop in the middle, elastic layer of the skin, called the dermis. It is made up of fibers called collagen that allow your skin to stretch and then shrink back into shape. If this layer of skin is continuously stretched over a long period of time, the elasticity breaks down and the skin tries to remedy the problem by increasing the amount of collagen in the over stretched area. This is what then creates the scars in the dermis which show through to the epidermis (top layer of the skin).
However, second theory believes that the term stretch mark is a misnomer and they are not caused by the stretching of the skin at all. It has been suggested that stretch marks are caused due to an increased level of a hormone called glucocorticoids, circulating through the bloodstream. This hormone is secreted by the adrenal glands and it is increased during pregnancy, adolescence, with obesity, Cushing's disease and weight lifting. The glucocorticoids affect the dermis by preventing the fibroblasts from forming collagen and elastin fibers that are required to keep growing skin taut. Dermal tearing then follows as there is a lack of supportive material when the skin is being stretched. So the stretching may determine where the stretch marks will occur but the actual stretching is not seen as cause of stretch marks. It has also been suggested that some people are more genetically prone to stretch marks than others. Skin type may be a factor; dryer skin has less elasticity than oily skin, and more prone to stretch marks. Stretch marks can also develop more easily in skin with a high proportion of rigid cross-lined collagen that occurs in teenagers.
Third and last theory on the cause of stretch marks is that they can occur due to the abnormal collagen formation as a result of medications or chemicals that interfere with collagen formation. It is also suggested that some medications that are hormonal or steroid based may cause stretch marks.