hi, Causes can be skin infection (bacterial or fungal) lead to replicate themselves and create bad odour,some times genetic or bad hygiene. Most excess sweating is due to excess sweat glands or their hyper stimulation. Here are some tips to stop this sweating or its odours. 1) If you have eczema or dermatitis or allergy then first take proper antibiotics or anti fungal as per your dermatologist opinion. 2) Always take balanced diet and drink plenty of water daily. 3) Avoid tight fitting clothes rather wear loose clothes. 4) Wear cotton material clothes and avoid synthetic silk. 5) Bath with antibacterial soap like dettol,savlon 6) Always clean groins,twice or thrice with brush during bathing. 7) Use antiperspirants and deodorants together like aluminium chlorhydrate or zirconium,one will block perspiration and other will mask the smell. 8) Use antibacterial creams or hand sanitizers on groins. 10) Curtailing excess tea or coffee.