What Causes Constant Headaches,low Fever And Watery Eyes?

my friend has not been keeping well for almost two years. last to last year she had jaundice and typhoid. but recently she had a bad stomach ache and got to know she had intestinal infection which corroded the layer of it too. for which the medicines have been given and the treatment is on. for last one week she is having a constant low fever, headache, body ache, numb fingers, watery eyes. why is this happening???? she has been getting the tests done, but the results are negative!