A virus is a microscopic parasite that depends on living cells for its survival. Once viruses gain entry to the body, they start destroying healthy cells by consuming the nutrients in them. Viruses also use healthy cells as their breeding grounds. This usually leads to health issues and diseases, which can trivial or fatal in nature.
Common Cold
The common cold is a viral infection caused by a virus that affects the upper respiratory tract. It usually manifests as a runny nose, cough, constant sneezing or sore throat. According to the Mayo Clinic, more than 200 viruses are responsible for common cold, rhinovirus being the most common. Common cold viruses usually enter the body through the nose or mouth. The cold is a harmless infection, and recovery takes one or two weeks.
Chickenpox
Chickenpox is a highly contagious disease. Four million children in America per year became infected with the chickenpox virus before the chickenpox vaccine became available, according to the Mayo Clinic. Signs are a red rash and small blisters, or pox, that eventually break open. These rashes are often accompanied by fever, headache, cough and loss of appetite. The pox normally develop on the face, chest, scalp and back. After infection, virus can be transmitted to another person within 48 hours.
Influenza
Flu is a respiratory disease, mainly caused by the influenza virus. According to the New York State Department of Health, 5 to 20 percent of the population is diagnosed with flu annually. Influenza symptoms include high fever, headache, sore throat and muscle aches. Diarrhea, nausea and vomiting may also occur. Respiratory droplets that are released into air by infected people coughing and sneezing spreads the virus to healthy people.
Hemorrhagic Fever
Viruses belonging to four different categories cause viral hemorrhagic fever (VHF). Early symptoms are muscle aches and fever. However, as the virus progresses, it often causes internal and external bleeding, because VHF affects the vascular system of the body. These viruses make the blood vessels porous, which can lead to minor or massive bleeding. Patients bleed under the skin, internally, or even from the eyes or mouth with this affliction. VHF affects internal organs, particularly the liver, lungs and kidneys. It is often fatal.
Meningitis
The fluid that surrounds the brain and spinal cord, cerebro-spinal fluid (CSF), becomes affected by the virus that causes meningitis. The meninges protects the spinal cord, brain and the CSF. Enteroviruses affect the CSF, causing headaches, high fever and stiffness in the neck. Other symptoms include nausea, sleepiness and vomiting. In many cases, meningitis is caught by being in contact with an infected person.
