A layer of cells around an ovarian follicle that produce androgens.
Why it matters for PCOS
Theca cells are the layer of cells surrounding each follicle in the ovary. When stimulated by luteinising hormone (LH) from the pituitary gland, theca cells produce androgens such as testosterone, which neighbouring granulosa cells then convert into estrogen. In PCOS, theca cells tend to be more active and overproduce androgens, and this is one of the biological reasons behind symptoms such as acne, excess hair growth (hirsutism), and irregular periods.
Theca cells are not tested directly. Instead, a doctor assesses the effect of their activity through blood androgen levels, such as testosterone, as part of a PCOS evaluation.
This glossary is education, not diagnosis. For your own situation, ask a doctor or pharmacist.