what causes skin cancer?

Answer 1

Risk factors for nonmelanoma skin cancer include:

Having a skin type that sunburns easily. People with light skin color, freckles, blond or red hair, and blue or light-colored eyes have sensitive skin and are prone to sunburn.
A history of severe sunburns, especially during childhood.
A family history of skin cancer or a personal history of skin cancer.
Celtic ancestry, such as Irish or Scottish.
Being older than 40.
Living close to the equator, where the sun's ultraviolet (UV) rays are stronger.
Working outside without protecting your skin from the sun.
Infection with the human papillomavirus (HPV).
Xeroderma pigmentosum, a rare genetic disorder that causes extreme sensitivity to ultraviolet radiation.
Being male. Men develop skin cancer more often than women.
Smoking.
Repeated exposure to X-rays, certain chemicals (such as arsenic, coal tar, creosote), and radioactive substances (such as radium)
Basal cell and squamous cell carcinomas can occur in people with dark skin, but these cancers are much more common in people with light skin.

The risk of squamous cell carcinoma is increased in people with scarred skin (such as from burns) and in people who have had organ transplants and take medications to prevent rejection of the new organ.



Risk factors for melanoma include:

History of exposure to ultraviolet (UV) radiation.
Sun exposure is the single most important risk factor for melanoma. Extensive exposure to the sun can occur during childhood, in jobs that require a person to work outside, and during outdoor activities.
UV exposure at tanning salons is just as risky as sunbathing.
History of sunburns, especially during childhood.
Previous melanoma or other skin cancer.
Family history of melanoma or FAM-M syndrome.
Atypical moles (dysplastic nevi).
50 or more moles.
White race, especially people who have fair skin that burns rather than tans, red hair, or blue eyes.
Many (extensive) freckles on the upper back.
Other cancers such as leukemia or lymphoma.
Impaired immune system.
Moles that are present at birth, especially if the moles are larger than 20 cm(7.9 in.) (giant congenital melanocytic nevus).
A rare inherited disease called xeroderma pigmentosum. This is a disease in which the body cannot repair damage to cells by UV radiation from the sun.
PUVA treatment, used to treat skin conditions such as psoriasis.

Answer 2

1

Answer 3

Skin cancer occurs when errors (mutations) occur in the DNA of skin cells. The mutations cause the cells to grow out of control and form a mass of cancer cells. Skin cancer begins in your skin's top layer — the epidermis. The epidermis is a thin layer that provides a protective cover of skin cells that your body continually sheds. Visit skincancerclinic for more information.

Answer 4

To much sun. The UV rays burn your skin and skin gets infected..

If you know you have skin cancer you'll have a mole looking scab on your arm or wherever.

Go to the doctor for more information!

Answer 5

This is just one possible way but, I think it's one of the more common ones.... UV radiation causes skin cancer by physically damaging DNA. UV radiation evokes a specific change in the DNA called a thymine dimer. Thymine (T) is one of the four base pairs of DNA and what happens is that instead of bonding to adenosine (A) across from it, it bonds to another thymine (T) beside it. If it gets fixed, it's no problem, however if it does not... it can cause tons of problems, Cancer being one of them.



From Wiki:
Thymine dimer
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A thymine dimer is the covalent bonding of two adjacent thymine residues within a DNA molecule, often catalyzed by ultraviolet radiation or chemical mutagenic agents. It is an example of a more general type of DNA damage known as a pyrimidine dimer which as the name suggests can occur between any adjacent pair of pyrimidine bases (such as between 2 cytosines or a cytosine and uracil). Excision repair enzymes and the DNA repair system can often recognize and repair this type of damage by the large kink in the DNA that it causes. In many organisms (excluding placental mammals such as humans), DNA photolyases can repair the damage directly by cleaving the dimer.

Unrepaired or mis-repaired thymine dimers and the resultant mutations can contribute to the development of skin cancers.

Here's A Picture (I know it's a long site!)
http://images.google.ca/imgres?imgurl=http://www.mun.ca/biology/scarr/T-T_dimer.gif&imgrefurl=http://www.mun.ca/biology/scarr/Thymine-Thymine_Dimers.html&h=350&w=600&sz=16&hl=en&sig2=UKYBl0GgJMJ0VyxUM2VvzQ&start=1&tbnid=PV9U6Od-uFM1mM:&tbnh=79&tbnw=135&ei=agPZRfzOLKjAiQHjlLjyCA&prev=/images%3Fq%3Dthymine%2Bdimer%26gbv%3D2%26svnum%3D10%26hl%3Den%26sa%3DX

Answer 6

Hey there,
Psoriasis is not fun to have and the outbreaks can be unbearable, but there are things you can do to help alleviate the symptoms. Home remedies are a cheap and easy way to find relieve.


You can find some of the most popular home remedies available to treat your psoriasis on this site: http://psoriasis.toptips.org

Answer 7

Any skin constant irritation can lead to skin Ca. e.g. due to hydrocarbons used in tar or talcum etc., or the other chap has replied as Sun which is due do ultraviolet rays .

Answer 8

Harmful UV rays caused by the sun use sunscreen!

Answer 9

the sun