I tend to sweat very easy and always have dark circles under my eyes?

Unrelated: No relationship between hyperhydrosis and dark circles. The skin of the lower eyelid area is so thin that we can actually see the circulation beneath the skin causing dark circles.

Dark circles: Dark circles are related to systemic allergies, lack of sleep, excessive stress, illness, dehydration, hereditary pigmentation in dark skinned individuals, and other issues. The easy sweating is probably unrelated.