I gained 10 pounds in 4 months. no cause. i am eating less and healthier, exercise, hydrated etc. all labs normal. thyroid, kidney, liver, heart. no explanation. what could it be? cancer ? hormones ? i am a biological male?

That is not a huge gain. Important that you feel healthy and have checked out normal on lab investigations. 1 check your wt machine for accuracy. 2 weigh yourself same time when you do.3 wear the same type of clothes each time.4 Reduce or eliminate junk food, too much alcohol, sodas. 5Continue and increase your daily exercise. 6 dont weigh daily- maybe once a week. You should be fine