Sun Spots: What They Are, Why They Appear, and How to Treat Them

You noticed a flat brown mark on your cheek or the back of your hand, and you can't remember it being there a year ago. You're wondering if it's just from the sun, if it will fade on its own, or if it's something you should worry about. In most cases, what you're seeing is a sun spot, a harmless sign of past UV exposure that's extremely common as we get older.

Still, not every brown spot is innocent, and a few simple checks help you know the difference. Here's what sun spots actually are, why they show up, the treatments that work best, and the warning signs that mean it's time to see a dermatologist.

What are sun spots?

Sun spots are small, flat, darkened patches of skin that appear on areas exposed to the sun over many years. Doctors call them solar lentigines (one is a solar lentigo), and you'll also hear them called age spots or liver spots, though they have nothing to do with the liver. They are benign, meaning not cancerous, and develop because of how your skin responds to ultraviolet light.

Individual spots are usually uniform in color, with a clear, well-defined border. They tend to be tan, brown, or sometimes nearly black, and most measure anywhere from a couple of millimeters to a couple of centimeters across. You'll most often find them on the face, the backs of the hands, the shoulders, the upper back, and the arms, exactly the places that catch the most sun.

• Flat (not raised) and smooth to the touch
• Uniform tan-to-brown color throughout
• Well-defined, clear edges
• Typically 2 to 20 mm in diameter
• Found on sun-exposed skin: face, hands, shoulders, arms

What causes sun spots?

Sun spots are caused by chronic UV exposure. Ultraviolet light speeds up your skin's production of melanin, the pigment that gives skin its color. On skin that has been exposed to the sun for years, that melanin can clump together or be produced in unusually high concentrations, creating the concentrated dark patches you see. Tanning beds and lamps deliver the same UV damage, so they cause sun spots too.

Anyone can develop them, but some people are more prone. They become very common after age 50 and appear in up to 90% of fair-skinned (Caucasian) people over age 60. People who burn easily and have lighter skin tones (Fitzpatrick types I and II) are at higher risk, and younger people who spend a lot of time outdoors or in tanning beds can get them as well. They are rare in children under 12.

Sun spots vs. skin cancer: how to tell the difference

This is the part that matters most. Sun spots are harmless, but certain skin cancers, especially a type of melanoma called lentigo maligna, can look like an ordinary brown spot in the early stages. A true sun spot stays flat, keeps one even color, and holds a steady, well-defined shape over time.

Be cautious with any spot that looks or behaves differently. A useful starting framework is the ABCDE rule used for melanoma: Asymmetry (one half doesn't match the other), Border irregularity, Color that varies within the spot, Diameter larger than a pencil eraser, and Evolving, meaning changing in size, shape, or color. If a spot checks any of these boxes, itches, bleeds, or simply looks different from your others, it deserves a professional look. Because spots can be hard to judge by eye, the American Academy of Dermatology recommends having a board-certified dermatologist confirm the diagnosis before you treat anything cosmetically.

How to treat and fade sun spots

Sun spots don't need treatment for your health; people fade them for cosmetic reasons. Once a dermatologist has confirmed a spot is benign, there are two broad approaches: topical creams, which are cheaper and lower-risk but take weeks to months, and in-office procedures, which work faster but cost more and carry more risk. Combination treatment tends to give the best results.

A 2025 systematic review of 41 clinical trials (3,234 patients) found laser therapy to be the most effective option overall, with picosecond lasers clearing 67.9 to 93.0% of spots and intense pulsed light (IPL) reaching 74.6 to 90%. Other approaches help too but generally clear fewer spots. The right choice depends on your skin type, the number and location of spots, your budget, and your tolerance for downtime, which is exactly the kind of thing to map out with a clinician.

• Lasers (picosecond, Q-switched) and IPL: most effective, faster, higher cost
• Topical mequinol 2% + tretinoin 0.01%: 52.6 to 80% efficacy, works especially well on the face
• Cryotherapy (freezing): roughly 37 to 71% clearance, long used as a first-line option
• Chemical peels: about 47% of patients saw 50% fading; combining with microdermabrasion improves results
• Microdermabrasion: around 40% saw complete disappearance, rising to 50% when paired with peels

How to prevent new sun spots

Treatment is only half the story. Sun spots can come back, and new ones can form, if your skin keeps getting UV exposure, so daily sun protection is the foundation of any plan. This is also the single best way to stop spots from appearing in the first place.

Strict, consistent sun protection genuinely works. The AAD recommends a layered approach you can build into your routine without much effort.

• Apply a broad-spectrum, water-resistant sunscreen with SPF 30 or higher every day
• Reapply every two hours outdoors, and after swimming or sweating
• Seek shade, especially between 10 a.m. and 2 p.m. when UV is strongest
• Wear protective clothing, a wide-brimmed hat, and UV-blocking sunglasses
• Skip tanning beds and sun lamps entirely

When to see a dermatologist

See a dermatologist if you have a spot that is changing, growing, itching, bleeding, or looks noticeably different from your other spots, or if you simply can't tell whether a mark is a harmless sun spot or something else. Any new or unusual pigmented spot in an adult is worth a professional evaluation, because catching a skin cancer early makes it far more treatable.

It's also smart to start with a dermatologist even if you only want spots gone for cosmetic reasons. A clinician can confirm the diagnosis, rule out anything concerning, and recommend the treatment most likely to work for your skin type while minimizing the risk of darkening or scarring. If you'd like a convenient first step, Nolla can help you get your skin reviewed by a clinician and point you toward a personalized plan.