Early physical symptoms include dizziness, tinnitus (ringing in the ears), insomnia, daytime drowsiness, loss of appetite, a tendency towards diarrhea - often alternating with constipation, cold hands and feet, a tendency towards sweating (some people have the opposite symptom and do not sweat at all), flushing or reddening of the skin - particularly on the face and neck. Some people blush frequently, but others do not blush at all. Asthma is a symptom of chronic mercury poisoning. Digestive disturbances are also common.