Understanding Stretch Marks Part II: Causes & Diagnosis

. 2 min read

Stretch marks is one of the most common skin conditions and yet is not completely understood by most. The most important goals of stretch mark treatment are: stopping new ones from appearing, and healing old ones. In part I of this series, we explained the prevalence and symptoms of stretch marks. The way to treat any condition is to understand it better - in part II of this three-part series on Understanding Stretch Marks, we dive into details of its causes and diagnosis.


  1. Weight gain
  • The primary reason for stretch marks is tearing of the dermis due to distension of skin, caused due to weight fluctuations and an increase in cortisone levels, which occurs in response to stress.
  • Higher cortisone levels are known to worsen the gravity of stretch marks by reducing the skin’s pliability. This occurs due to inability of fibroblasts to form collagen and elastic fibres, which help in maintaining the skin’s firmness. Thus, lack of supporting structures of skin, leads to dermal and epidermal tearing, which eventually leads to scarring.
  1. Pregnancy
  • In pregnancy, 50-90% of women are affected with striae gravidum due to sudden weight gain and hormonal changes. The more the weight gain and increase in BMI during pregnancy, the more is the risk of developing stretch marks. Higher neonatal birth weight also contributes to the same.
  • Striae gravidum develop due to tearing of the dermis, when estrogen and relaxin hormones combine with higher cortisol levels during pregnancy.
  • This softens the pelvic ligaments, making them flexible, which causes atrophy and loss of rete ridges, particularly in rapidly growing areas during pregnancy, like abdomen and breasts.
  • They are more common in first pregnancies and in women with lower maternal age.
  1. Puberty
    In puberty, the body goes through a lot of hormonal changes and rapid growth spurts, leading to the appearance of striae, which occur on breasts, hips and thighs for females, and shoulders and back in case of males.

  2. Genetic factors
    Genetic factors like genes, race, family history are also determinants in the appearance of striae.

  3. Medical Conditions-*

  • Certain medical and hormonal disorders, like Cushing’s Syndrome or Marfan Syndrome are also known to cause stretch marks.
  • In Cushing’s Syndrome, there is over-production of cortisol, leading to rapid weight gain, especially in abdomen, causing stretch marks to appear in that area. It also causes the skin to become thin and fragile, which makes it more susceptible to scarring.
  • In Marfan Syndrome, there is weakness and decreased elasticity of body tissues, which has the same above effects.
  1. Certain Medications
    Prolonged usage of topical corticosteroid creams and lotions decreases collagen levels of the skin, leading to thinness of skin and a greater risk of developing stretch marks.

Stretch marks are easily diagnosed upon observing the skin of the affected area. A history of weight gain or weight loss, or pregnancy makes the diagnosis clear.

Stretch marks do not cause any medical threat, but they may sometimes be associated with an underlying medical disorder, like, Cushing’s Syndrome or Marfan Syndrome, which must be identified and treated first. It is always best to consult a dermatologist for stretch marks.

There are ways to help heal stretch marks, and in the upcoming blog post we will explain its prevention and treatment. Stay tuned!