Mark it once you can do it without this page open.

How to do it

  1. Apply broad-spectrum sunscreen, SPF 30 or higher, 15 minutes before going out, using about a shot glass worth for the whole body.
  2. Cover the spots men miss: ears, the back of the neck, the scalp where hair is thin, and the backs of hands.
  3. Reapply every two hours, and after swimming or heavy sweating.
  4. Wear a hat and sunglasses and seek shade in the middle of the day.
  5. Once a month, check your whole body in a full mirror, with a hand mirror or a partner for your back.
  6. Look for the warning signs: asymmetry, ragged borders, several colors, bigger than a pencil eraser, or any change.
  7. Photograph moles you want to watch so you can compare.

Stop and call a professional if

  • A mole or spot changes in size, shape or color, bleeds, itches or will not heal: see a doctor or a skin specialist.
  • Severe sunburn with blistering over a large area, fever or chills: get medical care.
  • This page explains what to watch for; it cannot tell you what is wrong. Only a clinician who examines you can.

Common mistakes

  • Only using sunscreen at the beach.
  • Applying a thin layer once in the morning.
  • Forgetting the back and the scalp.
  • Using tanning beds.

Quick self-check

Three questions. Your last score is kept in this browser.

1. How often should you reapply sunscreen outdoors?
2. Which mole should you show a doctor?
3. Which spot do men most often miss?

Teach this to someone

A one-page sheet for showing a friend, a roommate or a kid: what to say, what to show, and one question to check it landed.

Sources

  • National cancer prevention guidance on skin cancer, current edition. Checked September 28, 2026.

Last reviewed . First published .