A recent study of middle aged black women reveals that nearly 30% have sustained permanent scalp and hair damage, possibly due to tight braids and weaves.Black women often maintain these styles for long periods of time, and the stress they exert on the scalp can lead to the development of pus-filled bumps, says the lead researcher, Angela Kyei, M.D., a dermatologist and chief resident at the Cleveland Clinic’s Dermatology and Plastic Surgery Institute.