Causes and Diagnoses

Melanoma Causes and Diagnoses

The exact cause of melanoma is unknown, but certain factors can increase your risk of developing melanoma. Risk factors include:

  • Age: Melanoma is more common in older individuals, but it is one of the most common cancers in younger individuals
  • Gender: Men have a higher overall risk; women are most at risk before age 40
  • Exposure to sunlight's UV rays
  • Tanning bed and sunlamp use: Artificial tanning has been linked to an increased melanoma risk.
  • Having abnormal or many moles
  • Having light hair and fair skin
  • Family history of melanoma
  • Personal history of melanoma
  • Certain rare, inherited conditions, such as xeroderma pigmentosum (XP)
  • A weakened immune system


Northwestern Medicine dermatologists assess and diagnose moles and melanoma by conducting skin examinations and taking samples of suspicious-looking moles (biopsy). Dermatologists may also recommend a yearly skin exam for people who have numerous moles or an increased risk of melanoma and skin cancer.