• Hair may fall out in larger than normal quantities, may generally become thinner, may fall out in patches, or may fall out altogether.
• When it affects men, male pattern baldness tends to start at the temples and top of the head, and may eventually progress to complete baldness of the scalp.
• Less frequently, women may also be affected by male pattern baldness, in which case it tends to cause hair thinning, rather than a completely bald scalp.
• Alopecia areata is a condition characterised by circular patches of hair loss on the scalp or other parts of the body that may be up to 5 centimetres in diameter. In some cases the hair grows back over weeks or months, but in other people the hairless patches persist for longer.
• Hair loss may cause some people to become very self-conscious, and can damage self-esteem , especially if it occurs early in life or is severe.
• Some types of hair loss are permanent, while others are temporary.

Common causes of hair loss include:

• Hereditary factors, which are responsible for many cases of baldness (especially male pattern baldness, in which testosterone affects the hair follicles).
• Hormone imbalance. For example, female pattern baldness involves various factors, including an excess of the male hormone testosterone, and consequently often develops after menopause. Other hormonal issues that may be involved in hair loss include thyroid hormone irregularities, insulin resistance, and polycystic ovarian syndrome.
• Immune system dysfunction. For example, alopecia areata is caused by an autoimmune disorder.
• Chemotherapy, oral contraceptive pills, corticosteroids and some other medical treatments can the hair or cause to fall out.
• Trauma to the hair, which may be caused by pulling on it (e.g. as a nervous or absent-minded habit), rubbing or scratching the scalp, vigorous brushing, wearing tight ponytails or buns, or curling the hair tightly in rollers. The use of harsh chemicals may have a similar effect.
• Ringworm of the scalp may cause the hair to break close to the scalp in the affected area.
• Poor nutritional status tends to lead to poor hair health, and may cause hair loss in some cases. Inadequate consumption of protein may be a factor, along with low levels of essential fatty acids, vitamin A, iron, zinc, and antioxidants.

Additionally, a certain degree of hair loss is one of the normal consequences of ageing. Temporary hair loss can also occur during pregnancy, or following surgery or a period of ill health.

• Biotin may help to strengthen brittle nails, improve splitting and chipping, and increase nail thickness.
• Omega-3 and omega-6 fatty acids are important for the structure and function of cell membranes. They are essential for skin and hair growth and help to maintain general health and wellbeing.