Symptoms of Weil syndrome usually start abruptly, with Headache, disturbances in consciousness, pain in muscles and abdomen, a stiff neck, lack of appetite (anorexia), chills, Nausea, Vomiting, and Fever. Prostration, coughing, expectoration of blood-stained sputum (hemoptysis), and nosebleed (epistaxis) may also occur. Yellowing of the skin (jaundice), bleeding in muscles, gastrointestinal tract, and visceral organs may be widespread. Small purplish-red spots (petechiae) may appear, caused by hemorrhages in the skin. Enlarged lymph nodes, and continued Fever may occur for several days. Respiratory distress syndrome which includes great Difficulty breathing and dangerously low levels of oxygen in the blood (hypoxemia) may sometimes develop in Weil syndrome.
Signs of liver and kidney dysfunction usually appear from the 3rd to the 6th day. Kidney abnormalities may include the appearance of protein (proteinuria), pus (pyuria), or blood in the urine (hematuria), and an excess of urea in the blood (azotemia). The kidney is often enlarged, and its capsule is tense. Bleeding in many places throughout the body may occur due to injury of tiny blood vessels (capillaries). A low number of blood platelets (thrombocytopenia) may also occur. Damage to the liver is usually minimal and complete healing almost always occurs. Fever usually abates on the 7th day, but it may be recurrent for weeks. After age 50 the prognosis for Weil syndrome is less optimistic than for younger people.