Flu starts abruptly and knocks you off your feet, while a cold creeps up gradually. We explain how not to confuse them, who is at risk of complications, and when to see a doctor immediately.
The measles virus can stay in the air for up to two hours and cause up to 18 secondary cases. Here's what is known about the course, complications, and protection through vaccination.
Two viruses that cause no symptoms for years and then lead to cirrhosis and liver cancer. How hepatitis B and C are transmitted, why they are detected late, and which tests are needed.