Typical causes of hair loss include stress, poor nutrition, medications, male baldness and female hair loss during pregnancy and menopause.


The normal hair follicle goes through growth and rest cycles. The period of growth usually lasts 2 to 3 years during which the hair grows an average of ½ to 1 inch per month. This is followed by a rest period in which the follicle shuts down, releases the hair strand and rests for several months. Once the rest period is over, the growth cycle will begin again.

A period of stress may cause the hair follicle to be pushed into the rest cycle early. This type of hair loss may be caused by emotional stress such as death of a loved one, a lost job or a divorce. It may also be caused by physical stress such as a high fever, surgical procedure, metabolic disturbance or sudden weight loss. Though stress is a major factor is sudden hair loss, once the stress period is resolved the hair will usually begin to grow back on its own.

Poor Nutrition

Hair growth is very dependent upon getting proper nutrition. The body requires adequate amounts of protein, along with other nutrients to produce hair strands. The hair is comprised of a substance called keratin and is mainly comprised of amino acids and proteins. Trace nutrients such as iron and sulfur are also required for hair growth.

Adequate protein consumption, healthy fatty acids and a balanced diet including vitamins and minerals is essential to maintain hair growth and prevent hair loss. Nutritional deficiencies may also contribute to slow hair growth but correcting the diet will usually correct the problem.


Some medications may contribute to hair loss. Starting a new medication may cause sudden hair loss that will be noticed several weeks after beginning the medication. Medication known to contribute to hair loss may include hormonal treatments, arthritis medicines, some high blood pressure medications, blood thinners and of course – chemotherapy. If the medication is discontinued, the hair will likely begin to grow again.

hair loss from medications

Male Baldness

Baldness in men is a fairly common occurrence as they age. Male pattern baldness can often be inherited and typically emerges with hair loss above the forehead but may start at the crown of the head. If a man has a grandfather who was bald, he is more likely to become bald.

Male pattern baldness may sometimes start as early as the late teens and is related to the production of testosterone. A form of testosterone known as DHT causes the hair follicles to begin to shrink. As they shrink, the hair will become thinner and eventually fall out as the hair follicle becomes too small to produce hair. Minoxidil, a topical medicine can be applied to the scalp to prevent further thinning but it is rarely successful at regenerating lost hair follicles. Hair transplants may also be performed to replace lost hair.

Female Hair Loss

Hair loss in females occurs quite frequently after pregnancy, but may have other causes such as thyroid disorder, hormonal imbalance or autoimmune diseases. During pregnancy, hormones prevent hair loss. Many pregnant women notice that their hair is thicker and more luxurious but several months after birth, they will suddenly lose the hair. This is because the hormones have prevented the hair follicles from entering the resting phase. When the pregnancy hormones drop, all of those hair follicles will enter the resting phase at once. This condition will most likely remedy itself within a year.

Women are also more likely to have conditions such as low thyroid, autoimmune diseases such as lupus, and other hormonal imbalances that are known to contribute to hair loss. These conditions may sometimes be treated with medications but not always. Some women may also get a form of pattern baldness related to male pattern baldness caused by a loss of estrogen and progesterone during menopause. Losing the production of estrogen and progesterone allows the testosterone in the female body to be more active and cause the same type of hair follicle shrinkage seen in men.

Though hair loss can be startling and emotionally painful, most types of hair loss are treatable. Ensuring proper diet, minimizing stress, getting plenty of sleep can help eliminate many of the causes.

Brian Johnson MD

Brian Johnson MD

Dr. Brian Johnson is a professor of dermatology. He has conducted numerous research studies about hair loss and it's effects on the human psyche. Dr. Johnson has written for Maclean's, Motherboard, the National Post, and the Huffington Post.
Am I Losing More Hair Than Normal? Previous post Am I Losing More Hair Than Normal?
Vitamins for Hair Loss that promote Hair Growth Next post Vitamins for Hair Loss that promote Hair Growth

Leave a Reply

Your email address will not be published. Required fields are marked *