When wearing locs, watch for thin roots, thinning edges, excessive weight, pain, persistent scalp irritation, or weak and compromised areas. These can be signs that the hair or scalp is experiencing too much tension, weight, or stress and should not be ignored. And remember: there is no prize for avoiding shampoo. Your scalp naturally produces oil, sweat, and buildup, so regular, appropriate cleansing is an important part of maintaining a healthy scalp and healthy-looking locs.