There are three major types of skin cancer. The two most common are squamous cell carcinoma and basal cell carcinoma. The third is melanoma; while it is less common, it is the most dangerous kind.

Young woman's back being examined at a dermatologists

Squamous Cell Carcinoma – Causes, Signs and Symptoms

Squamous cells lie just below the outer surface and function as the skin’s inner lining. Most often, squamous cell carcinoma occurs on areas of your body exposed to the sun, such as your face, ears and hands. People with darker skin are more likely to develop squamous cell carcinoma on areas that aren’t often exposed to sun as often, such as the legs and feet. Squamous cell carcinoma may appear as a firm, red nodule or a flat lesion with a scaly, crusted surface.

Basal Cell Carcinoma – Causes, Signs and Symptoms

Basal cells produce new skin cells and live beneath the squamous cells. Basal cell carcinoma usually occurs in areas of your body exposed to the sun, such as your neck or face. It may appear as a pearly or waxy bump or a flat, flesh-colored or brown scar-like lesion.

Melanoma – Causes, Signs and Symptoms

Melanoma begins in skin cells called melanocytes. Melanocytes are the cells that make melanin, which give skin its color. Melanin also protects the deeper layers of the skin from the sun’s harmful ultraviolet (UV) rays. When exposed to the sun, the melanocytes produce more melanin, causing the skin to tan, but too much exposure to any type of UV light (including tanning beds) may cause the melanocytes to grow abnormally and become cancerous.

In men, melanoma most often shows up on the upper body, between the shoulders and hips and on the head and neck, whereas on a woman, it’s more likely to develop on her lower legs. People with darker skin have a higher concentration of melanin, a skin pigment that acts a bit like sunscreen, but this does not make them any less susceptible to the sun’s radiation. Melanoma often appears under their fingernails or toenails, on the palms of their hands, and on the soles of their feet.

While your chances of getting melanoma increase as you get older, it’s one of the most common cancers in young adults (ages 25 to 29). It is a serious and sometimes life-threatening cancer. If it is not caught early, it can grow deeper within the skin and metastasize, or spread, to other parts of the body, making it difficult to treat. While skin cancer doesn’t discriminate, there are certain factors that can increase your risk:

  • Light-colored skin, hair and eyes
  • People with moles or abnormal moles
  • Excessive sun exposure
  • History of sunburns
  • Family history of skin cancer
  • Personal history of skin cancer
  • Weakened immune system
  • Sunny or high-altitude climates
  • Exposure to certain substances such as arsenic