Viral infections are illnesses one gets from tiny organisms that use body cells to make more copies of themselves (viruses). They commonly cause respiratory and digestive illnesses, but they can also infect other parts of the body. A virus is a type of germ so small, that it can be seen only under a microscope. Viruses carry a small piece of genetic information (DNA or RNA) inside a protective coating (capsid). It is like an envelope carrying instructions. Body cells are like a factory. They contain instructions and all the equipment needed to build proteins and make more cells. If viruses want to replicate, they have to break into body cells and use our system to do it. Viruses replicating is what makes one sick with a viral infection. Types of viral diseases include, respiratory infections, digestive system infections, viral haemorrhagic fevers, sexually transmitted infections, skin rash causing infections, neurological infections and congenital infections. Respiratory system infections are commonly spread as droplet infection and affect nose, throat and lungs. It can cause common cold, cough, throat pain, breathlessness, pneumonia. Diarrhoea and or vomiting, occur if viruses like Norovirus, rotavirus, e.t.c.,, affect digestive system, which commonly gain entry in the body through poor food, drink and or hand hygiene. Hepatitis viruses affect and damage the liver. Viral hemorrhagic fevers like , ebola, severe dengue, etc. cause high fever and bleeding and even death. Unprotected sex with an infected partner, results in viral infections like Human immune deficiency virus(HIV), genital herpes, genital warts, human papilloma virus, e.t.c. They can cause blisters or rashes over private parts and or around and even cancer. Viruses that affect skin cause rashes blisters, e.t.c. on skin which are itchy. Examples are measles, chicken pox, etc. Neurological infections can be serious like meningitis, encephalitis poliomyelitis, e.t.c. Common viruses causing it are like polio, rabies, e.t.c However respiratory and other symptoms can occur with any virus affecting any system. In congenital viral infection, one is born with the infection. Infection is passed from Mother to baby when in womb or during birth. They can cause vision or hearing loss, delayed mile stones or neurological problems. Examples being Rubella, Zika, virus, HIV, e.t.c. Viral infections are diagnosed on the basis of strong suspicion after taking a good clinical history and examination of the patient. Complete blood count can help to exclude bacterial infection. Identification of many types of viruses is possible through serological tests. Nasal swabs or body fluid samples are taken for this purpose. Tests like X-rays, C.T. scans , abdominal ultrasound, help to ascertain the damage if any and its extent in the affected organ. Most of the viral infections are treated just symptomatically. Like taking steam inhalation for cold and cough paracetamol for fever. Specific medications are available only for some viral infections, example being HIV hepatitis B and C. These medicines stop viruses from making more copies of themselves. In some cases, convalescent plasma has been beneficial in treating the infection, i.e. by using plasma from the blood of a person who has just recovered from that viral infection. It has helped in some cases of covid infection and ebola. Certain medications help in preventing infection or minimising it, after accidental exposure to a specific infection (post exposure prophylaxis) like HIV, hepatitis B, rabies, chicken pox. Antibiotics are not useful for viral infections and are given only if a bacterial infection is suspected. Many of the viral infections spread through contact with body fluids of the patients. Good hand washing is an effective way to prevent many viral infections. Good attention to food hygiene, safe sex, prevents digestive system infection and sexually transmitted diseases. Vaccinations are also useful in protecting against a viral illness. Vaccines are available for measles, Chickenpox, shingles, Covid-19, viral hepatitis A and B, influenza, Human papilloma virus (HPV), polio, rabies, Rota virus. A healthy life style, helps in prevention of any infection, including viral. But on becoming sick, medical help should be sought immediately.