Does dandruff cause hair loss?

Dandruff is a common condition in which flakes of skin appear on the head and hair, and can fall onto the shoulders. Dandruff can be caused by several skin conditions or infections, but is usually not problematic. It is not caused by poor hygiene, and stress and cold weather may make it worse.

Dandruff does not always cause hair loss, but hair that grows from an unhealthy scalp can be weaker and more brittle. If your dandruff is itchy and you scratch it, you may also damage the follicles, causing further hair loss.

Anti-dandruff shampoos, such as Head & Shoulders, are widely available. These shampoos contain anti-microbial substances, such as zinc pyrithione, which help to fight microbial causes of dandruff, but they also contain moisturising and cleansing ingredients which help to re-hydrate and prevent further damage to the scalp and hair. If your dandruff is itchy or sore, or does not go away after using anti-dandruff shampoos for several weeks, you may need to see your doctor for further advice.

Sources:

NHS > Dandruff 
Head and Shoulders > How to prevent hair loss due to dandruff 
Head and shoulders > How anti-dandruff shampoo ingredietns work