Hair loss

Hair loss can appear in many different ways, depending on the problem that's causing it. It can come on suddenly or gradually and affect just your scalp or your whole body. Some types of hair loss are temporary, while others are permanent.

Signs and symptoms of hair loss may include:

• Gradual thinning on top of head. This is the most common type of hair loss, affecting both men and women. In men, hair often begins to recede from the forehead in a line that resembles the letter M. Women typically retain a line of hair at the forehead but experience a broadening of the part in their hair.
• Circular or patchy bald spots. Some people experience smooth bald spots, often about an inch (2.6 centimeters) across. This type of hair loss usually affects just the scalp, but it sometimes also occurs in beards or eyebrows. In some cases, your skin may become itchy or painful before the hair falls out.
• Sudden loosening of hair. A physical or emotional shock can cause hair to loosen. Handfuls of hair may come out when combing or washing your hair or even after gentle tugging. This type of hair loss usually causes overall hair thinning and not bald patches.
• Full-body hair loss. Some conditions and medical treatments, such as chemotherapy for cancer, can result in the loss of hair all over your body. The hair usually grows back after treatment ends.

Risk factors

• Family history. Your risk of hair loss increases if relatives on either side of your family have experienced hair loss. Heredity also affects the age at which you begin to lose hair and the developmental speed, pattern and extent of your baldness.
• Hair treatments. Overuse or improper use of hair-coloring products, hair straighteners and permanent waves can leave your hair brittle and prone to breaking off at the scalp. Excessive hairstyling or hairstyles that pull your hair too tightly cause traction alopecia.
• Poor nutrition. Your hair may thin out if you skimp on good dietary sources of iron and protein, such as red meat, nonfat dairy products and iron-fortified cereal. Hair loss related to poor nutrition often accompanies eating disorders and crash dieting.​

When to see a doctor

Talk to your doctor if you notice sudden or patchy hair loss or more than usual hair loss when combing or washing your hair. Sudden hair loss can signal an underlying medical condition and may require medical treatment.