What Diseases Cause Excessively Dry Hair?

There can be many reasons for excessively dry hair. Environmental pollution, frequent styling, blow drying and use of chemical shampoos and colouring can rob the hair of its softness and shine and make it dry. However, there are also many diseases that can cause very dry hair.

Hence it becomes very important to consult a doctor if your hair suddenly becomes extremely dry, as it could be a symptom of a disease that needs prompt treatment.

Why Do Diseases Cause Extremely Dry Hair?

Hair is made of keratin (a protein) and water. The hair grows luxuriantly with shine and gloss when it is well nourished with proteins, omega-3 fatty acids and nutrients. Hence, when a disease deprives the body of such nutrients, dry hair may result. Some hormones, such as those produced by the thyroid gland, directly control the absorption of proteins and minerals by the body and, therefore, the deficiency of such hormones because of disease naturally leads to dry hair.

Diseases That Deprive Hair of Nutrients and Make It Dry

Kwashiorkor is a malnutrition disease that causes dry hair due to protein deficiency. Both anorexia nervosa, an eating disorder wherein a person eats hardly any food because of the fear of gaining weight, and bulimia, another eating disorder wherein a person first overeats and then self-induces vomiting, fearing weight gain, produce dry hair symptoms by creating a nutrient shortage. Dry hair is caused by anaemia, a condition of iron deficiency in the blood. Menkes kinky-hair syndrome is a hereditary metabolic disorder that hinders copper absorption. Copper deficiency makes hair dry and brittle.

Diseases That Cause Extremely Dry Hair by Affecting Hormones

In the case of the thyroid disorder called hypothyroidism, thyroid hormone deficiency prevents protein assimilation, which leads to dry hair. Hypoparathyroidism causes a decrease in the PTH or parathyroid hormone, which hinders assimilation of vitamin D and calcium by the body, again causing dry hair. Another disease, Hashimoto's thyroiditis, also shows dry hair symptoms because it hampers functioning of the thyroid gland.


Dry hair is lusterless, rough in texture, unmanageable, lifeless and dull. It does not have enough natural moisture or oils in it. Combination of dry hair symptoms with some other unexplained symptom may indicate disease. For instance, dry brittle hair accompanied by sudden weight gain, fatigue and constipation could indicate hypothyroidism. You also need to visit the doctor for diagnosis of disease causing dry hair if you find that the dry-hair condition persists despite intensively caring for your hair.


The disease has to be cured for hair to get back its lustre. Besides this, gentle home care of dry hair can help the situation. Reduce use of harsh shampoos; use mild conditioners. Avoid blow drying and hair colouring with chemicals. Eat healthful, balanced meals. Consume more salmon, fish oil, flaxseed, hempnut seeds and oil, green leafy veggies, beans and walnuts. All these foods are abundant in the omega-3 fatty acids needed for soft, shiny hair.