Hi.. Thanks for the query.. As per your complain Hypersalivation can occur either due to increased saliva production by the glands and it is a hallmark symptom in case of Parkinsonism, it is also seen commonly in other diseases related to central nervous system. It can also be seen in conditions like GERD, Pancreatitis, liver diseases,oral ulcers, Newly wearing denture,medicines like Pilocarpine and toxins etc.. It can also be due to decreases ability to swallow the saliva like in case of tonsillitis, peritonsillar abscess,jaw fractures,epiglottitis, ad mumps which is parotid gland viral infection.. It is also seen in nervous system problems like Facial Palsy, Mysthenia Gravis, Parkinsonism etc.. At present your father is prescribed with a few Blood pressure reducing medications and he is recalled after one month for which the reason that i can gauge is the blood pressure reducing medicines at times causes reduced saliva flow and after taking for one month hopefully the flow can reduce.. You should also convince your father to stop smoking and drinking as it is rally harmful for the body and he should get a complete body evaluation or body checkup done.. For loss of weight you should not weight for a month and consult your treating doctor and get evaluated and get a proper diet plan from a registered dietician.. Give him a nutritious diet and ample of rest.. Treatment of Hypersalivation can be done only by treating the underlying cause.. Hope this helps.. Regards..