A disease is a physical condition that negatively effects the functioning or structure of a living organism, and this is not because of any direct external injury inflicted on the organism. Diseases are frequently viewed as common medical conditions which often correlate with certain distinctive symptoms and signs. They can be either acute or chronic, or be neither of these, depending on the specific type of disease and its causative agents. A number of diseases have been named, depending upon their general manifestations and their cause.
Some diseases are so rare that they are considered as fatal. One of the rarest such diseases is Non-Hodgkins lymphoma, which usually takes ten years to manifest. However, this does not mean that it may become life-threatening. Certain forms of cancer are also very uncommon, while most others are widespread in different parts of the world, and may affect millions of people.
Intractable fever, measles, diphtheria, pertussis, hepatitis B, rabies, strept throat, viral meningitis and anthrax are all infectious diseases, since they cause major harm to the body through their contagion. The only difference between them is their mode of transmission. Some of these diseases are also classified as noninfectious, because their causative agents do not remain in the organism after its elimination, like bacteria and viruses. Examples of noninfectious diseases are cancer and HIV. Cancer can be transmitted via a tumor, although this has not been proven conclusively in all instances.
Intrapersonal stress, anger, anxiety, and other types of psychological problems can affect one’s ability to resist infection. This may make them susceptible to infectious diseases that have similar manifestations. This is known as the stress-immune system. In the case of AIDS, the disease was caused by the immune system attacking cells that were infected with AIDS. This attack on the infected cells resulted in the cells becoming damaged, which allowed the HIV virus to take over the cells and reproduce itself inside the AIDS patient’s body. As the HIV virus can remain in the body for years, the risk of contracting the disease through contaminated food cannot be ruled out.
Scientists are currently trying to figure out how to prevent exposure to these microbes, but so far, there is no permanent cure for any of these diseases. Some can be controlled, though. Some researchers are focusing on developing drugs to strengthen the immune system. Other scientists are trying to develop ways to inhibit the replication of certain microbes.
The good news is that it is unlikely that any of these infectious agents will be able to wipe out every living thing on the planet. However, healthy persons are better protected from the dangers of most non-infectious diseases than they are from the dangers of some infectious diseases. A healthy person can generally defend against the common dangers of pathogens, because healthy persons’ immune systems usually have high-level defenses against these microorganisms. This means that a healthy person can normally fight off an infection. A healthy person also has other mechanisms that can help to prevent exposure to dangerous microbes. The best protection against pathogens is getting vaccinated or having protected intercourse.