Age spots are flat, brown patches on the skin that range from light tan to nearly black. They typically measure from freckle-sized to about half an inch (13 millimeters) across, though some grow to a few centimeters over time. If you’ve noticed new dark spots appearing on your hands, face, or shoulders, you’re likely looking at solar lentigines, the medical term for these common, harmless marks.
Color, Shape, and Texture
Age spots are light brown to black pigmented lesions with a flat surface that sits level with the surrounding skin. You can’t feel them by running your finger over them, which is one of their defining features. The color within a single spot is generally uniform, meaning the entire patch looks like one consistent shade of brown or tan without dramatic color variation from one edge to the other.
Their shape is usually oval or roughly circular with relatively smooth, well-defined borders. They can appear alone or in clusters, especially on skin that’s had heavy sun exposure over the years. When multiple spots sit close together, they can look like a larger irregular patch, but each individual spot tends to have a clean outline. Over time, age spots darken and grow slightly larger. Research tracking age spots over five years found that lesions increased in size and became noticeably darker as the underlying skin structure continued to change from cumulative sun damage.
Where They Show Up Most
Age spots develop on skin that has received the most UV exposure over your lifetime. The backs of the hands are the single most common location, followed by the face, forearms, shoulders, and upper back. They also appear on the chest and shins, particularly in people who’ve spent years in shorts or open-collared clothing. Skin that’s been consistently covered by clothing rarely develops them, which is a useful clue: if a dark spot appears somewhere the sun doesn’t reach, it’s worth getting it checked.
Age Spots vs. Freckles
Freckles and age spots look similar at a glance, but they behave differently. Freckles are largely genetic. They tend to appear in childhood, darken in summer, and fade in winter. Age spots are caused by accumulated photodamage to the skin over years of UV exposure. Once they appear, they don’t fade with the seasons. They stay put year-round and generally show up after age 40 or 50, though people with significant sun exposure can develop them earlier.
Freckles are also smaller and lighter, usually a reddish-brown scattered across the nose and cheeks. Age spots are bigger, darker, and more defined in their borders.
Age Spots vs. Raised Growths
A common source of confusion is the difference between a flat age spot and a seborrheic keratosis, a raised, waxy growth that also appears on sun-exposed skin as you get older. Seborrheic keratoses look as if they were dripped onto the skin by a candle. They’re slightly elevated, have a rough or scaly surface, and often have a distinctive “pasted on” appearance, as though you could peel them off. They can be tan, brown, or black.
Age spots, by contrast, are completely flat. If a spot feels bumpy, rough, or raised when you touch it, it’s likely something other than a simple age spot. Seborrheic keratoses are also benign, but their raised, textured look can make them more alarming than a flat age spot, even though neither is dangerous on its own.
When a Spot Might Not Be an Age Spot
The real concern with any new brown mark on your skin is whether it could be melanoma. The ABCDE criteria, developed by the National Cancer Institute, outline the key visual differences:
- Asymmetry: One half of the spot doesn’t match the other. Age spots are generally symmetrical.
- Border: Ragged, notched, or blurred edges, with pigment spreading into the surrounding skin. Age spots have clean, defined borders.
- Color: Multiple colors within the same spot, including shades of brown mixed with white, gray, red, pink, or blue. Age spots are one uniform color.
- Diameter: Larger than 6 millimeters (about the size of a pencil eraser), though melanomas can sometimes be smaller. Most age spots fall within this size range too, so size alone isn’t a reliable indicator.
- Evolving: A spot that changes in size, shape, or color over weeks or months. Age spots change slowly over years, not weeks.
A single age spot that has stayed the same color and shape for months or years is almost certainly benign. A spot that is changing rapidly, has an irregular border, or contains multiple colors within it deserves a closer look from a dermatologist. The key distinction is stability: age spots are boring. They show up, they stay flat, they don’t change much. Anything that looks dynamic or uneven is worth flagging.
Why Age Spots Form
Your skin produces pigment as a defense against UV radiation. Over decades, repeated sun exposure causes pigment-producing cells in certain areas to go into overdrive, depositing extra pigment in concentrated patches rather than distributing it evenly. The structural architecture of the skin in those areas changes at a cellular level, with the normal circular arrangement of cells at the skin’s surface becoming irregular and deformed. This is why age spots are permanent: the underlying skin structure has been altered by years of UV exposure, not just temporarily tanned.
People with lighter skin tones develop age spots more frequently and at younger ages, but they can appear on any skin tone with enough cumulative sun exposure. Tanning beds accelerate the process just as much as natural sunlight.