Introduction
A disease represents a medical condition (abnormal condition of any organism) that impairs bodily functions and which can lead to death. It is always associated with symptoms and signs of appearance. Diseases can be caused by external factors (this is the case for infectious diseases) or it may be caused by internal dysfunctions (these are called autoimmune diseases). In a more common approach, a disease often is related to any human condition that causes pain, distress or dysfunctions. The most common diseases are caused by external factors such as viruses. A virus is a small infectious agent. Its primary capability is that he can replicate itself inside the living cells of other organisms. Viruses can infect all types of organisms such as animals, plants, bacteria and so on. Also an important fact is that viruses are the most predominant form of biological entities, covering almost all ecosystems on Earth.
Viruses
As you may have read before, viruses are the most abundant type of biological entity. The first appearance in a public article of viruses was in 1892, when a Russian botanist discovered a non-bacterial pathogen that infected tobacco. A few years later, the tobacco mosaic virus was discovered by a Dutch botanist and microbiologist (Martinus Beijerinck discovered it in 1898). Nowadays about 5000 viruses are described in detail, although there are millions of different types. These viruses represent a very good source of diseases because they can spread by various ways such as through air, through water, (in the plant’s cases through insects), exposure to infected blood or sexual contact and many other distinct ways. Viruses can cause death but also can cause only small health problems (because of the immune responses of the different bodies).
Diseases
Diseases and viruses are the number one cause of death in the world. Also if a certain human dies because of diseases and viruses, it is told that he died of natural causes. In medicine, the term of disease refers to the incapability of normal functioning for several organs and systems. It is notable the fact that diseases and viruses are not the only cause of death, but this doesn’t make them less dangerous. The worst part of a disease is not that it affects your body, but that it has a negative effect over your emotional state too. Having many diseases as a child, it can lead to a negative personality in the future.
Treatment
Diseases and Viruses are a common affection in the world, but they can be prevented and treated. The most used techniques of disease prevention are exercise (you should be careful to adequate exercise), sanitation, proper nutrition, self-care and vaccination. Some diseases and viruses can be cured, others not. When the medicine first began to show results, many of the known diseases in that time couldn’t be cured, but as the time passed by and the medical equipment and technology began to be more and more modern, people found cures for several diseases. Currently about 30% of the known diseases have a cure and even more are being studied.
