Tanning is a way of protecting our skin from exposure to the sun. When the skin comes in contact with UV radiation, pigment-producings cell or melanocytes produce extra melanin, which is the pigment that gives us our colour, in order to absorb the nasty UV radiation and protect the inner cells from damage. So you can safely conclude that the quicker you tan, the less prone are you to getting skin cancer. If you burn easily and don't tan quickly, you should be more wary of the sun. But there are pros and cons to either side, and if you tan easily, you are also more prone to unsightly hyper-pigmentation (darkening of the skin).

What causes uneven pigmentation�

When the skin is over-exposed to the sun to a great degree, melanocytes (pigment producing cells) may go into a panic, and produce excessive pigmentation. So what, you ask. All that this means is that I turn a darker shade. Yes, that is true, but the problem is, due to the panic, the nature of the cells may get altered, and you may find that they start producing more melanin permanently. Your tan just may become permanent. However, this is not where the problem lies, as many people would be happy to have a permanent tan. The problem is, not all cells react the same, so while some cells produce extra melanin or colour, others don't, which leads to pigment patches. To make matters worse, certain melanocytes may shut down due to excessive sun exposure, as they are unable to cope. The skin around this cell consequently turns white, and will never tan. (These white patches should not be confused with leucoderma.) This condition is known as hypo-pigmentation, and is even more severe than hyper-pigmentation, as the white skin patches are particularly prone to skin cancer due to their inability to tan.

Prevention

The sun is the skin's greatest enemy, and while a certain amount of sunlight is desirable, UV radiation is not. The sun quickens ageing of the skin and the formation of wrinkles, and causes age spots and freckles, in addition to skin cancer and pigmenation disorders.

Shield your body from the sun as far as possible to prevent discolouration. Wear full sleeves if you are going to be in strong sunlight, cotton, so you do not feel too hot. If you would rather wear short sleeves, make sure you apply adequate sunscreen not just on your face, but on your arms as well.

What is the cure

If you already have discolouration, you could visit a dermatologist who would be able to prescribe appropriate treatment. Mild chemical pigment peels are also available wherein the outer discoloured layer of the skin is peeled off. But unless your skin tone is starkly uneven, or if you have discolouration or patches on your face, I do not see the need for going in for this. Homeopathy medication has also been known to treat pigmentation, but while there are no guarantees, this medication is safe, has no side effects, and is worth a shot.

• Drink at least ten glasses of water in a day. Drink two glasses of water in the morning when you wake up, before brushing your teeth.
• Try applying lime (nimbu) to the discoloured area. Do this everyday, and wash off after 15 minutes. You could also apply lime to the affected area at night once in a while, and wash off in the morning when you bathe.
• Bleaching the affected area once a month will lighten it too. Do not bleach when pregnant.
• Various creams and lotions that claim to reduce pigmenation are also available. You could try them to see if they work for you.