Is being bald or losing hair hereditary in males? females?

Yes: Both graying and baldness are mostly genetic- ask your older relatives when they lost their hair or started graying. Sometimes, medical illness or certain stressors or medical treatments(like chemo) are the cause. Male pattern baldness is carried by the females- so it is possible to have a bald father and sons with full heads of hair. Women can also have male pattern baldness.