Some causes of hair breakage are bleaching, perms, ponytails and braids, brushing too much and shampooing too much. Extensions and weaves, blow-drying and coloring can also cause hair damage.
Bleaching changes the structure of hair by penetrating the cuticle and removing pigment. Hair becomes weaker as a result of bleaching, which can lead to breakage. Perms weaken hair by breaking and re-forming inner bonds in hair. Permed hair, over time, can become brittle and dry.
Wearing ponytails or braids every day can cause permanent hair damage. Putting hair in a ponytail or braiding when it is wet causes even more harm because hair is more fragile when wet. Pulling ponytails or braids tightly also increases the odds of hair breakage. Brushing hair too much often leads to split ends and breakage as a result of consistent friction. Using a poor-quality brush can also result in breakage from snags.
Shampooing hair too much washes away natural moisture from hair and makes it dry. Different washing frequencies are right for different hair types. Dull-appearing hair signals shampooing should be scaled back. Extensions and weaves can cause hair breakage similarly to how ponytails and braids do. The breakage occurs at the roots, however.
Blow-drying or using a flat iron on hair daily can cause permanent hair damage over time. Heat causes changes to the hydrogen bonds that hold hair together. Hair coloring can result in dryness, especially if it is frequent. The damage, however, is not as great as in bleaching.