Maintaining a good head of hair may be harder than you think. Factors like environmental stress, hormonal imbalances and even fungal infections can all wreak havoc on your crowning glory.

To obtain shiny, silky tresses a la Chinese actress Zhang Ziyi (right), you have to take good care of both your hair and scalp.

Ms Leonica Kei, director of Philip Kingsley Trichological Centre, said: 'Hair is usually the first to suffer from any bodily upset and the last to benefit from an improvement.'

Mind Your Body combs through the most common hair and scalp problems.

DANDRUFF

What: A chronic scalp disorder marked by itchiness and excessive flaking. Seborrheic dermatitis, caused by the fungus pityrosporum ovale, is the most common cause.

Looks like: Red, greasy skin blanketed with flaky white or yellow scales. Affects not only the scalp but also other areas rich in oil glands, like the eyebrows.

Treatment: Use a medicated shampoo containing coal tar, zinc pyrithione or selenium sulphide and a scalp lotion with corticosteroid to stem the inflammation. Coal tar and selenium sulphide shampoos help stem and prevent cell turnover while zinc pyrithione is an anti-bacterial and anti-fungal agent which reduces the fungus that causes dandruff and seborrheic dermatitis.

PSORIASIS

What: A skin disorder which tends to run in families.

Looks like: Thick scales on the scalp and the scalp can be itchy and sensitive

Treatment: Use a medicated shampoo containing coal tar, zinc pyrithione or selenium sulphide and a scalp lotion with corticosteroid to stem the inflammation. Use regularly even after the condition improves.

ANDROGENETIC ALOPECIA

What: Common pattern hair loss, a permanent condition which can start any time after puberty.

Looks like: In men, it is characterised by a receding hairline and balding at the top of the head. In women, thinning of the hair is usually limited to the front, sides or crown.

Treatment: Oral medication called finasteride for male patients or topical medication called minoxidil lotion for male and female patients. Treatment should be continued indefinitely to maintain results. Wigs and hair weaving or transplants are also options for patients with advanced hair loss.

ALOPECIA AREATA

What: An autoimmune condition where certain white blood cells of the body fight the hair roots, leading to hair being shed.

Looks like: Hair loss usually occurs in small, round patches.

Treatment: A range of options (depending on the extent and severity of hair loss) including topical applications, injections of corticosteroids and oral medication.

TELOGEN EFFLUVIUM

What: Reactive hair loss due to underlying medical reasons like thyroid diseases. It can also be caused by a sudden stressful event that happened two to four months prior to the hair loss, like crash dieting or giving birth. Hair roots are pushed prematurely into the resting state of the hair cycle by a shock in the system and the affected hairs fall out.

Looks like: Sudden and diffuse hair loss over the whole scalp.

Treatment: If the condition is triggered by stress, the hair loss is temporary and scalp hairs will grow back. If not, the patient should see a dermatologist who will then assess and diagnose the problem.