It wasn't there yesterday. In fact, you have no idea where it came from. But today you can't miss it -- a large, ugly bruise, spreading like an ink stain over your lower arm.
What's worse, these unsightly blotches are becoming more familiar as you age. Should you worry? Probably not.
We bruise when blood vessels beneath our skin rupture and bleed. As alarming as these purplish marks can be, they're usually harmless. With passing years, however, they become increasingly common with the mildest bump or blow.
"As we age, the outer layer of skin -- the epidermis -- gets thinner," explains John E. Wolf Jr., M.D., head of the residency training program at Baylor College of Medicine's department of dermatology. At the same time, the inner layer of skin, called the dermis, is also getting thinner. The dermis -- the layer containing the blood vessels -- thins due to falling production of the protein collagen and damage to collagen from sunlight.
As a result, he explains, blood vessels have less support and protection. The fragile skin also is more likely to tear. Because of reduced collagen production and less efficient wound healing, small white scars often remain, says Dr. Wolf.
Dr. Wolf says the problem usually starts to show up after age 55, but long-time sun worshippers may see changes earlier.
For many people, in fact, sun damage "is thought to account for about 90 percent of age-related changes in the skin."
Moreover, the problem may be compounded if you smoke or use certain medications.
Why do your bruises look worse than they used to? "When we're younger, the good support of the dermis limits the spread of the bruise," says Ivor Caro, M.D., director of the international training program for Harvard Medical School's Department of Dermatology. "In older people those vessels are so poorly supported that not only may that particular bleed under the skin spread, but multiple vessels may bleed."
Your bruises also may linger. Although the purplish discoloration may last days or weeks, a brownish discoloration -- caused by an iron-containing pigment called hemosiderin -- may linger for months or never disappear.
The overwhelming majority of bruises are no cause for worry. But sometimes it's best to check with your doctor because bruises may signal a more serious health concern:
If you've become prone to bruising even though your skin doesn't appear to have thinned significantly.
If you find bruises in an unusual area, such as your torso.
Here are some drugs that may increase your chance of bruising. Never discontinue any medication without consulting your doctor.
Nonsteroidal anti-inflammatory drugs, such as ibuprofen.
Anticoagulants such as coumadin or heparin.
Corticosteroid-containing medications (applied to the skin, taken orally or injected).
Medications that affect coordination can make you more prone to falls.
Because bruising can happen without your awareness, it can be difficult to avoid. Still, experts say these strategies may help:
"Vitamin C plays an important role in the production of collagen," Dr. Wolf says. "Some people who are not getting enough vitamin C in their diet or by supplementation may be more prone to bruising." Ask you doctor about supplements.
Help protect your skin from injury by wearing long sleeves and long pants when diving into a chore that may injure your skin.
Chalk up one more reason to quit smoking. "It's been shown that smoking has a tendency to decrease collagen production and may lead to wrinkles and bruisability," explains Dr. Wolf.
If you've received a bump that may bruise, immediately apply ice, which causes blood vessels to constrict and may help minimize bleeding.
"You need to be aware that your skin is thinner and try to be very careful to avoid bumping the skin," advises Dr. Wolf. "Minor injuries that didn't used to make a difference will cause bruising" as you age.
That will relieve dryness and make skin give more easily. Some people claim creams containing vitamins C or K may help prevent bruising, but experts say this has not been proven. However, a dermatologist can prescribe a retinoid cream or a skin preparation containing lactic or glycolic acid, which may help.
Although it may be too late to reverse the damage that's been done, try to reduce further harm by applying sunscreen and covering up while outdoors.