The causes of thinning hair on the sides include traction alopecia, heredity, and certain diseases. A type of baldness called pattern baldness sometimes causes thinning hair, as opposed to the crown area or hairline. Traction alopecia is a condition that refers to hair loss generated by hairstyles such as tight ponytails. When the hair is pulled away from the head, stress is exerted on the roots of the hair. Sometimes, permanent damage to the hair follicles can occur and the hair will not grow back.
Another cause of thinning hair on the sides is injury or scarring. Occasionally, the hair follicles become scarred by medical conditions such as autoimmune diseases and dermatological conditions. In addition, these conditions can damage the oil glands resulting in hair fallout. The underlying condition needs to be determined and managed before thinning hair on the sides can be treated. Hypothyroidism, or low thyroid, can also cause thinning hair, although this may be reversible after thyroid replacement hormone therapy has been initiated.
Stress can also promote thinning hair on the sides of the head and may even affect the entire scalp. When stress is managed, however, this type of hair loss generally resolves. When hair loss is attributed to stress or emotional distress, the health care provider can recommend a stress-management treatment plan, which might include medications, exercise, cognitive therapy, and dietary changes.
Treating thinning hair depends on the cause. Sometimes, hormonal fluctuations can cause hair to thin, and is occasionally noticed after childbirth or during the menopausal years. Patients who pursue hormone replacement therapy should talk with a doctor about the risks and benefits of this therapy. When thinning hair on the head is accompanied by hair loss on the rest of the body, further medical evaluation is needed. This may indicate a condition known as alopecia totalis, which is an autoimmune condition that can cause hair loss on the entire body, including the eyelashes and eyebrows.
A medication known as minoxidil may be helpful in promoting hair growth, however, it can cause side effects. Most side effects are mild, and include burning of the scalp, dryness, itching, and flaking. Rare, but serious side effects can also occur when using minoxidil, and may include difficulty breathing, chest pain, dizziness, and swelling of the extremities, stomach or face. If these symptoms occur, emergency medical intervention needs to be sought as soon as possible.