How do viruses cause diseases?

Viruses cause diseases by disrupting the normal functions of cells. Once inside a host cell, a virus can use the cell's machinery to replicate and produce more copies of itself. This replication process can damage the cell and interfere with its normal functions. Additionally, viruses can produce toxins that can further damage cells and tissues.

Some specific examples of how viruses cause diseases include:

* Influenza virus: This virus causes the flu, which is a respiratory infection. The virus can damage the cells in the nose, throat, and lungs, causing symptoms such as fever, cough, sore throat, and runny nose.

* HIV: This virus causes AIDS, which is a chronic, life-threatening condition. HIV targets and destroys white blood cells, which are essential for fighting off infections. As a result, people with AIDS are more susceptible to other infections and diseases.

* Ebola virus: This virus causes Ebola virus disease, which is a severe, often fatal illness. The virus can damage multiple organs and tissues in the body, causing symptoms such as fever, headache, muscle pain, and bleeding.

* Measles virus: This virus causes measles, a highly contagious childhood illness. The virus can cause a rash, fever, cough, runny nose, and red, watery eyes. In some cases, measles can lead to serious complications, such as encephalitis and pneumonia.

Viruses are responsible for a wide range of diseases, from the common cold to more serious illnesses such as AIDS and Ebola virus disease. Understanding how viruses cause diseases is essential for developing effective treatments and vaccines.