An itchy scalp, also sometimes known as scalp pruritus, can cause irritating and uncomfortable symptoms, including a strong desire to scratch the scalp frequently. Having an itchy scalp alone isn’t usually something you need to be worried about, although it can be incredibly frustrating for sufferers and may indicate another underlying condition. In this post we explain the science behind what causes an itch and look at some of the most common itchy scalp causes.

An itch is simply your body’s response when it suffers some form of skin irritation. This irritation can be triggered outside the body, such as when a plant rubs against your skin, or from something that has happened inside your body to cause the itch, such as an allergic reaction or skin condition like psoriasis.

When your brain detects an irritation, signals are sent to that location in an instant, causing you to scratch. The reason scratching an itch feels good is that it actually triggers tiny pain signals, which form a distraction from the irritation. In some cases, the pain-fighting chemical serotonin can be released, which may cause the area to feel even more itchy and increase the temptation to scratch. This can be a vicious cycle, leading to further irritation, which in turn leads to more itching, and so on. The scalp is one of the areas of the body most prone to becoming itchy.

There are a number of reasons your scalp might itch and we have outlined some of these causes below.

The most common cause of an itchy scalp is dandruff, a mild form of the condition known as seborrhoeic dermatitis (see below). Dandruff causes white or grey flakes to appear on the scalp and in the hair and people with the condition may find that their scalp is itchy too. The primary cause is natural yeast called Malassezia, to which some people are especially sensitive.