Hair loss is a common occurrence that affects everyone at some point in their lives. It can be caused by a variety of factors, including stress, poor diet, and underlying medical conditions. Hair loss can affect the scalp or the entire body, and can be temporary or permanent. It can be the result of heredity, hormonal changes, medical conditions, or a normal part of aging.
Thyroid problems are one of the most common causes of hormone-related hair loss. Too much thyroid hormone (hyperthyroidism) or too little (hypothyroidism) can cause hair loss. Treating a thyroid disorder can often reverse hair loss. Alopecia areata is a type of patchy hair loss that occurs suddenly and usually begins with one or more circular bald spots that may overlap.
Men may also experience hair loss due to hormonal changes as they age. Sudden hair loss can also be caused by thyroid problems, psoriasis, prescription drugs, and chemotherapy drugs. These triggers force the hair to suddenly move from the growth phase to the resting phase, which is when hair normally falls out. Your doctor can help you determine the cause of sudden hair loss and correct any underlying problems that may be contributing.
Chemotherapy and radiation therapy to the head or neck may cause all or most of your hair to fall out within a few weeks of starting treatment. It's not the amount of hair loss itself that causes sudden shedding, but rather the speed at which it moves from one phase to another. This means that you may continue to lose hair for up to six months, but the amount should decrease over time. If you notice sudden or patchy hair loss or more hair loss than usual when styling or washing your or your child's hair, it's important to see your doctor.