context: Maybe your scalp stings a little when you color your hair. Or the new shampoo you're using makes it burn. Or maybe your scalp just started itching for no reason you can think of. It's not surprising that scalps sometimes itch, sting, or feel prickly. Though your skull is hard, your scalp is quite tender. It has more blood vessels than any other area of the body and lots of nerve endings. Here are some common causes of scalp problems and what you can do about them. Treatments that color, bleach, or straighten your hair are the most likely hair products to irritate your scalp. If you use heat during processing -- to help lighten hair, for example -- the irritation can be worse. What helps: Always do a patch test to see how your skin reacts before using a new hair product. If it stings or itches, try a different brand. If you're coloring your hair, try a semi-permanent color or a rinse. Permanent color has an ingredient called PPDA that can cause an allergic reaction. To limit exposure to harsh chemicals, retouch the roots instead of doing all-over color every time. Or highlight instead of lightening all over. Fragrances and preservatives in shampoo irritate some people's skin. Not rinsing out shampoo well can also cause itching. What helps: Switch to a new shampoo. Look for fragrance-free, organic shampoo for color-treated hair or mild "baby" shampoos. Be sure to give your hair a good rinse. Winter weather can make your scalp flake and itch, especially if you live in a cold, dry climate. This usually goes away in summer, unless it's very hot and humid. Hot and humid weather can make scalps feel prickly. What helps: Try to keep indoor temperatures "just right" -- not too warm or too cool. Wash your hair less in winter to keep in oils and moisture that protect your scalp. Yes, your scalp can burn, too. If your hair is thin or you're bald, the sun can also damage your topmost skin over time, making it rough, dry, and scaly. This condition, solar keratosis, raises your risk of skin cancer. What helps: Wear a hat outside. Use spray sunscreen where you part your hair, or apply sunscreen on your head if you're bald, even on cloudy days. Make sure it's SPF 30 or higher and broad-spectrum. When your scalp's dead skin cells shed at a super-fast rate, you get itchy flakes. No one's sure what causes dandruff; it may be hormones. What helps: Shampoo often to get rid of dead skin cells. Leave the lather on your scalp for a few minutes before rinsing off. Every other hair washing, use dandruff shampoo. Don't avoid shampooing to control itchy dandruff -- that's a myth that doesn't help. If you are African- American, you may do better not washing your hair daily; try a medicated shampoo weekly. If you have a pileup of itchy scales, the problem could be psoriasis. With this skin condition, new skin cells are made faster than usual. What helps: See a skin doctor for any scalp itching or burning that doesn't go away. For psoriasis, prescription medication, scale softeners, and shampoo can help. A doctor can also find and treat other skin conditions that annoy your scalp. These can range from serious problems like skin cancer to less serious ones like acne or lice.