Homeopathy works on principle of symptom similarity. A medicine which is stronger in power but similar to the symptoms of the disease is selected. In acute diseases there is sometimes an intensification of already present symptoms. These may be mistaken for side effects. When you see such effect, all you need to do is stop the medicine. That will take care of the increased symptoms and the acute disease in question. In chronic diseases you don't see such reactions. But by and large , homeopathy has no side effects. On a lighter note, it either has effects or no effects.