Leptospiral infection in humans causes a range of symptoms, and some infected persons may have no symptoms at all. The disease begins suddenly with fever accompanied by chills, intense headache, severe muscle aches, abdominal pain, and occasionally a skin rash. The headache in leptospirosis is characteristically located at the bilateral temporal or frontal regions with throbbing pain. The person could also have pain behind the eyes and sensitivity to light. Muscle pain usually involves the calf muscle and the lower back. The most characteristic feature of leptospirosis is the conjunctival suffusion (conjunctivitis without exudate) which is not commonly found in other febrile illnesses. Other characteristic findings on the eye include subconjunctival bleeding and jaundice. Rash is rarely found in leptospirosis. When rash is found, other alternative diagnoses such as Dengue fever and Chikungunya fever should be considered. Dry cough is observed in 20% to 57% of people with leptospirosis. Thus, this clinical feature can mislead a doctor to diagnose the disease as respiratory illness. Additionally, gastrointestinal symptoms such as nausea, vomiting, abdominal pain, and diarrhea frequently occurs. Vomiting and diarrhea may contribute to dehydration in conjunction with kidney failure due to excessive urine output. The abdominal pain can be due to acalculous cholecystitis or inflammation of the pancreas. Rarely, the lymph nodes, liver, and spleen may be enlarged and palpable.