疲 is built from the 疒 (sickness) and 皮 components.
It reads ヒ like 皮, as do 被, 彼, and 披 — learn 皮 once and the family's reading comes with it.
A common word using 疲 is 疲れる (つかれる), meaning “to get (become) tired; to become fatigued”.
Kanji that look similar include 疾, 病, 症, and 疫.
