We all know that the sun’s rays can damage your skin. But did you know the sun also can damage your hair?

If your hair has prolonged exposure to the sun, UVA and UVB rays can damage the outside cover of the hair strand, called the cuticle.

Signs of sun damage to your hair include discoloration, dry and brittle strands, broken or split ends, thinning and frizziness. Damaged hair has a dry look and feel. Damaged hair also is unmanageable and won’t hold a curl or style. Usually, damaged hair dries quickly.

Your hair is particularly vulnerable sun damage if it’s fine or light-colored. You’re also more at risk for hair damage from the sun if you are African-American due to the flat and coiled shape of the hair

The good news is that you can take precautions to protect your hair from the summer sun. 

The sun’s rays act very much like bleach on hair, says dermatologist Wilma Bergfeld, MD. Bleach reacts with the melanin in hair and removes the color in an irreversible chemical reaction. Bleach also damages the hair’s cuticle and protein, which is called keratin.

Finer, lighter hair lacks the thickness or pigment that can protect it from the sun’s rays, Dr. Bergfeld says. Darker, coarser hair usually is oilier, and its thickness, darker color and oil covering help to protect it. African-American hair is fragile due to its shape, which is thin, flat and tightly coiled, Dr. Bergfeld says.

Making matters worse

Hot flat irons or rollers, chlorinated water in swimming pools or lightening your hair can make it more vulnerable to the summer stresses of heat and sun. All of these damage your hair’s keratin.  The damaged protein allows sun and heat to penetrate the hair more easily and results in a fragile hair strand.

“If you bleach or highlight your hair, you’ve damaged the hair already,” Dr. Bergfeld says. “To add to that by swimming in a chlorinated pool, or sitting out in the sun, you’re going to have very significant hair breakage.”

Steps toward protection

What to do if you want to be outside during the summer but don’t want a headful of frizzy, dull and damaged hair? Dr. Bergfeld offers these tips:

  • Go out early or late in the day, just as you would to protect your skin.
  • Wear a hat or cover yourself with an umbrella. “There is not a cosmetic product out there that acts like a sunscreen” for your hair, she says.
  • If you swim in a chlorinated pool, make sure you rinse the pool water — which contains salt and chlorine — out of your hair with clear water.

Use a hair conditioner appropriate to your hair color and type, as well as the climate. If you have fine hair, Dr. Bergfeld recommends looking for a volumizing formula.