Is baldness always hereditary?

Causes of "baldness" Alopecia is commonly known as hair loss, hair thinning, & balding. While genetic causes (like male pattern balding) are common, other causes exist: hormones, infections, autoimmune causes, metabolic (e.g. Chemotherapy), nutrition (e.g. Vitamin deficiencies), trauma (e.g. Tight braids), neoplastic (some cancers), etc. A dermatologist can help determine the cause & discuss treatment options.
No but commonly is. Due to various of genetic expression, baldness is not always hereditary but it certainly is likely to be transmitted with varying degrees of expression.