Symptoms of Viral Diseases
A virus is a small submicroscopic viral agent which replicates within an organism’s living cells. The word virus comes from the Greek word virusus which means ‘not alive’. Viruses affect all living things, from plants and animals to bacteria, viruses, and microorganisms, such as Archaea and E. coli. There are various different types of viruses, with some having damaging effects on other organisms. Some viruses are responsible for generating disease; however, most viruses merely replicate themselves without harm.
A virus that replicates by invading an organism and establishing a cellular host relies on the appropriate biological mechanisms to invade and establish itself. There are three common types of pathogens which include anthrax, hepatitis B virus, and HIV/AIDS. A bacterium, virus or parasite can also cause disease, although these agents are not classified as viruses. The majority of bacteria, viruses and parasites are not classified as viruses; however, some parasites can cause certain types of cancers.
Common Cold: Common colds are caused by virus particles interfering with the respiratory system. Symptoms of a common cold include sore throat, cough, headache, fever, fatigue, and skin rash. There are a few rarer symptoms, such as breakdown of the lung tissues or abnormalities of the heart or brain. Some individuals may experience a persistent and extremely severe cold, even leading to death.
Mumps: Mumps are caused by the common cold, but they are also commonly caused by the Epstein-Barr virus (EBV), which is part of the larger family of viruses known as the herpes simplex virus. Mumps are highly contagious and often spread through bodily fluid, such as saliva. The virus particles can reside in the nasal cavities, mouth, and rectum. Unlike common colds, mumps symptoms do not usually last for more than a day or two, and most people only develop mild or minor symptoms after developing mumps. A few people with very weak immune systems may also experience a fever, loss of appetite, and swollen lymph glands.
Allergies: Many different kinds of viruses cause various kinds of allergic reactions in humans, and these can be symptoms of a number of different diseases. Most often, allergies involve a reaction to one of the thousands of substances that are consumed in the United States each day. Examples of substances that are frequently found in the environment or that humans can become infected with include chemicals (such as pesticides), household chemicals, pollen, and dust. In rare cases, organisms that are normally harmless can become infectious, and these can cause serious health problems. In the case of food allergies, a food intolerance may be the cause of symptoms, as well as a reaction to an allergen.
Viruses can spread between living cells and reproduce themselves. These viruses can invade the bodies of healthy cells and reproduce within them, causing serious health problems. The viruses that spread from living cells can sometimes remain inactive and undetected, while dormant viruses can replicate and spread throughout the body and cause many symptoms. However, these dormant viruses are a major part of the reason why so many viruses exist and continue to circulate.