The uncontrolled or abnormal growth of skin cells is termed as skin cancer. Skin cancer mainly occurs in areas that are exposed to the Ultraviolet sun rays. However, it might also appear in areas that do not receive any sunlight. For instance, cancer cells may spread to other parts of the body such as the bones or internal organs. Therefore, it’s important to look for warning signs of skin cancer on the entire body so that treatment begins as soon as possible to prevent the spread of cancer to other parts of the body.

Types of skin cancer and their causes include the following:

1. Basal cell carcinoma (BCC)
It is the most common form of skin cancer. It starts in the basal cells within the skin that are responsible for the development of new cells as the older ones die. It appears as pinkish patches or transparent bumps. Though they occur on the skin areas that are exposed to the sun, such as head, neck, and arms, they may also appear on other parts of the body such as legs, chest, abdomen, etc. It is also caused when the skin is exposed to indoor tanning lamps or tanning beds. It can affect the surrounding tissues and grow into bones and nerves, causing disfigurement.

Though the exact cause behind this type of skin cancer is often not clear, the possible causes of BCC are:

• Long-term sun exposure: BCC is caused when the skin is exposed to the harmful UV rays of the sun for a long-term. Protecting the skin with layers of sunscreen and avoiding the sun might prevent the occurrence of BCC.
• Mutation in DNA: The basal cells are located below the outer layer of skin known as the epidermis. The role of these cells is to produce new cells by pushing the older ones towards the surface of the skin where they die and are disposed of. Mutation of the DNA of these cells leads to their rapid growth instead of the death of older ones. This will cause abnormal cells to accumulate and form a cancerous tumor.

2. Squamous cell carcinoma (SCC)
It is the second-most common type of skin cancer; it forms in the middle and outer layers of the skin. They are characterized by dry and scaly patches, which further lead to SCC. SCC, if left untreated, can spread to other parts of the body.

This form of cancer generally occurs in people who experience years of exposure to ultraviolet radiation from the sun or tanning beds. It is also caused by a mutation of DNA of squamous cells that leads to abnormal cell growth.

3. Melanoma
It is the deadliest type of skin cancer that mostly develops in moles or appears as new dark spots on the skin. They occur in the melanocytes cells that produce melanin, a pigment that provides color to the skin. This form of cancer can also appear in the eyes and, in rare conditions, in different internal organs.

Similar to the other forms of skin cancer, melanoma is also caused as a result of prolonged exposure to UV rays and mutation of DNA in the cells.