Irregular heartbeat and disturbances of the rhythm of the pulse. That Lyme disease actually causes palpitations of the heart is an indication of how seriously the disease affects the body. The palpitations will usually be accompanied by lightheadedness. However, while this disruption of the heart rhythms is a definitive symptom of Lyme disease, the palpitations themselves are not serious or life-threatening.
Hepatitis and inflammation of the liver. It is important to diagnose Lyme disease in the initial stages, as the disease becomes progressively more serious with time. If left untreated, hepatitis, which is an inflammation of the liver, can occur. This is an extremely serious condition, and the patient will suffer from intense pains in the stomach, indications of jaundice, such as yellow eyes, a queasiness of the stomach and darkened urine. At this point, restrictions to the diet and other serious lifestyle changes are necessary to treatment.