Hi and welcome to HCM Ammonia like body odour can be caused due to many reasons. Does the individual have any previous history of illnesses or regular medication. AMmonia odor can be due to build up of this waste in the body either because it is not being excreted properly or because there is too much for the body to digest. I would advise a general liver and kidney function test. Also drink a lot of fluids and increase fibre intake to help waste removal. Keep a check on the amount of fried foods, fats and heavy proteins as these can cause extra ammonia build up. Since it is present easily, even things like excess physical activity, occasional alcohol that is not broken down properly, use of certain medicines etc can cause the smell. Infections such as candida fungal infections have been known to cause it. I would advise you to start with these small lifestyle changes and check. If it is persistent, do consult a doctor to rule out other medical causes as mentioned. Hope this helps.