We lose hair all the time – 50 to 100 hairs a day, to be precise. But we don’t usually notice this constant renewal. Hair is important to us, to our sense of identity and self-esteem. It can be alarming when you see lots of hair on your brush, in the plug hole or across the carpet. We don’t always find a cause, and hair grows back, but it’s worth seeking a doctor’s opinion in certain circumstances, in case a medical problem is to blame. Let’s cut through to the important bits: what’s causing it and what treatments might actually work.
Psoriasis is one condition that can affect the scalp – you might notice salmon pink or red areas, especially above the back of the neck or behind the ears, and these areas might feel a bit itchy. Targeted scalp treatments prescribed by your doctor can help. Infections can cause hair loss – fungal infections cause hair loss in patches. You might notice a crusting or flaking over the area and it’ll feel itchy. This is more common in children and is contagious, so all children in a family should be treated with antifungal treatment. Your doctor will be able to diagnose this, and they may take skin scrapings to be sure, before starting treatment.
Some medical conditions can cause hair loss, including lupus, underactive or overactive thyroid gland (hypothyroidism or hyperthyroidism), iron deficiency anaemia and zinc deficiency. Alopecia is a specific autoimmune condition whereby the body attacks its own hair follicles – this is very difficult to treat so seek help early if you notice shiny bald patches where hair is not growing back, or you notice loss from other hairy areas such as the eyebrows, genital area or chest in men. Hair loss can be a response to stress or trauma in the body. If you are very unwell, your body pours all its resources into getting you better. This can be anything from fighting a chest infection to having your appendix surgically removed. Many with COVID-19 infection have reported hair loss after recovery. Your body is in survival mode, and diverts nutrients away from maintenance of non-essential areas, such as hair growth. You may only notice the hair loss several weeks or months after the trauma. This temporary loss of hair is called telogen effluvium, and it will usually grow back. Chemotherapy is designed to attack fast-growing cells like cancer cells. Unfortunately it doesn’t discriminate, so hair follicle cells are also a target, and those on chemotherapy often get overall hair loss, which can be very distressing, on top of feeling unwell and coming to terms with their diagnosis. Hair does grow back gradually after treatment stops. Polycystic ovarian syndrome (PCOS) may cause hair loss, with a relative excess of androgen hormones. You will also experience absent or irregular periods, acne and excess hair around the chin, upper lip or chest.
Any reversible cause needs to be treated before the body diverts nutrients back to new hair growth. As hair only grows about 1cm per month, it can take a couple of years to feel like your usual head of hair is back. See your doctor if you are suddenly losing hair, if you have bald patches or it’s coming out in clumps, or if the scalp is itchy or burning. You should see your doctor if it’s causing you particular concern, or if someone in your family has alopecia or an autoimmune condition. Some hair loss may be permanent if hair follicles have been destroyed, so it’s important to seek help early. Your doctor can examine you and send you for any relevant investigations, including blood tests, skin scrapings, and they may refer you to a dermatologist. It’s hard to determine a cause of hair loss for some, especially if they’ve been well mentally and physically and all tests are negative. In this case, it may be part of the ageing process or it may be a question of patiently waiting for hair to grow back.