What Could Cause Increased Growth In Body Hair?

I am a 34-year-old, white male with no pre-existing health conditions. The growth of my arm hair has increased noticeably in the past year, especially on the area just below the inside wrist. Hair growth has also increased on other parts of the arms, and has slightly increased under the arms. A small, but noticeable increase has also occurred on my chest and stomach. Are these changes considered typical in a man my age?