What are infectious diseases?
Infectious diseases are disorders caused by organisms — such as bacteria, viruses, fungi or parasites.
Many organisms live in and on our bodies. They're normally harmless or even helpful. But under certain conditions, some organisms may cause disease.
Some infectious diseases can be passed from person to person. Some are transmitted by insects or other animals.
You may get others by consuming contaminated food or water or being exposed to organisms in the environment.
Disease-causing organisms also can be passed by indirect contact. Many germs can linger on an inanimate object, such as a tabletop, doorknob or faucet handle.
When you touch a doorknob handled by someone ill with the flu or a cold, for example, you can pick up the germs he or she left behind. If you then touch your eyes, mouth or nose before washing your hands, you may become infected.
Signs and symptoms vary depending on the organism causing the infection, but often include fever and fatigue.
Mild infections may respond to rest and home remedies, while some life-threatening infections may need hospitalization.
Many infectious diseases, such as measles and chickenpox, can be prevented by vaccines.
Frequent and thorough hand-washing also helps protect you from most infectious diseases.
Symptom
Each infectious disease has its own specific signs and symptoms.
General signs and symptoms common to a number of infectious diseases include:
- Fever
- Diarrhea
- Fatigue
- Muscle aches
- Coughing
When to see a doctor
Seek medical attention if you:
- Have been bitten by an animal
- Are having trouble breathing
- Have been coughing for more than a week
- Have severe headache with fever
- Experience a rash or swelling
- Have unexplained or prolonged fever
- Have sudden vision problems
Source:
https://www.mayoclinic.org/diseases-conditions/infectious-diseases/symptoms-causes/syc-20351173
