Virus Viral Diseases

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Introduction To Viral Diseases

Viruses are a type of microorganism which are very small infectious agents. DNA or RNA is the piece of genetic material that is enclosed in a protein coat and these lead to the formation of viruses. In the cells of the body, these viruses invade and use those cell's components as they help them to multiply. Infected cells often get destroyed by this process and cause incredibly widespread infection which is called viral disease. Viral diseases are also considered contagious because when the virus enters the human body, it begins to multiply and it spreads from one person to the other. Viral diseases include:

  • Chickenpox

  • Influenza

  • Herpes

  • AIDS

  • Human papillomavirus (HPV)

  • Infectious mononucleosis

Symptoms of Viral Diseases

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Viral disease symptoms vary on the basis of virus type, health history and age of the patient, body area infected, and other factors. Symptoms of viral diseases can include:

  • Irritability, rash, sneezing.

  • Swollen lymph nodes and tonsils. 

  • Flu-like symptoms include (headache,   fever, cough,  sore throat, aches, fatigue, and pains).

  • Gastrointestinal disturbances like nausea, diarrhea, and vomiting.

  • Malaise (general ill feeling).

  • Stuffy and runny nose, postnasal drip, or nasal congestion.

  • Unexplained weight loss.

Serious Symptoms 

In some cases, viral diseases cause serious complications like pneumonia or even life-threatening conditions.

  • Change in conscious level or alertness.

  • Green, yellowish or brownish phlegm produced by deep, wet chest cough. 

  • High fever, seizure, chest pain, stiff neck.

  • Lethargy or unresponsiveness

  • Shortness of breath, or difficulty in breathing, wheezing.

  • Jaundice.

Types of Viral Diseases

1. Respiratory Viral Diseases

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These diseases commonly affect either the upper or lower part of the body's respiratory tract. Examples include common cold, influenza, SARS, etc.


These Respiratory viruses are either transmitted through droplets generated by sneezing, coughing, or by close contact with contaminated objects. 


These infections mostly heal on their own. But some medications can be prescribed that help reduce symptoms like cough suppressants,  Tamiflu (antiviral drug), Nasal decongestants, and pain relievers.

2. Gastrointestinal Viral Diseases

As the name suggests, these infections affect a human's digestive tract. The viruses that cause the disease are mostly responsible for causing a condition called gastroenteritis, also named as the stomach flu and it is also termed to be contagious. 

For Example astrovirus, norovirus, rotavirus infections


These diseases are spread due to contamination of water and food with feces or using personal objects and utensils of infectious persons.


No treatment is available.  It resolves on their own.  Meanwhile, the person is advised to take plenty of fluids to make a balance of the loss due to vomiting or diarrhea.

3. Exanthematous Viral Disease

These diseases are caused by Exanthematous viruses that are responsible for causing skin rashes. Most of the viruses of the category are highly contagious. 

For Example Rubella, Smallpox, Chickenpox, Measles.


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Most of the viruses are transmitted from the droplets generated through sneeze and cough of the infected persons. 

Many diseases like chickenpox and smallpox are spread through the contact of fluid present in the broken skin lesions and diseases like chikungunya are spread through the mosquito bite.

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It can be cured by managing symptoms. For Chickenpox, antiviral drugs like acyclovir are given to the patients. Some other fever-reducing medications like acetaminophen are also given to other diseases that come under this category.

List of Viral Diseases in Humans

S No.


Affected Organ

Name of Virus 




WBC (Defensive system)


The immune system of the body becomes weak


Dengue fever

Whole-body particularly head, eyes, and joints 

Billions of virus

Pain in joints, muscles, head, and eyes



Backbone nerve, Throat


Intestine and backbone cells get destroyed, fever, body pain


Influenza (flu)


Mixo virus

Sneezing, suffocation, restlessness 


Chicken Pox


Variola virus

Reddish eruption on the body, high fever 




Varicella virus

Bile eruption in the body, light fever



Parathyroid gland


Difficulty in opening the mouth, high fever 






Reddish eruptions on the body





Pain in eyes, Reddish eyes


Hepatitis or jaundice 



Skin and eyes become yellow and urine too



Nervous System 

Rabies virus 

Due to the severe headache and high fever, the patient becomes mad.





High fever





Skin swells

FAQ (Frequently Asked Questions)

1. Name Any Two Diseases Caused by Viruses?

Cutaneous Viral Diseases

 These diseases result in papules or lesions that stick on the skin either after disappearing for some time and then come back after a long time. Examples include genital warts, oral, and genital herpes.

Hepatic Viral Diseases

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These results in affecting the liver by causing the inflammation of the liver. Some examples include hepatitis A, B, and C. No special treatment is available for a mild infection. Patients are advised to take proper rest and anti-inflammatories which helps in giving relief to the headache or pain and keeps them hydrated. Antiviral medications are also prescribed in some of the cases.

2. Name Some Diseases Caused by Viruses?

Common Cold:-

  • Pathogen: Rhinovirus 

  • Incubation period: 24 to 72 hours.

  • Symptoms: Scratchy or sore throat, nasal obstruction, sneezing, malaise, and rhinorrhea.

Infectious Mononucleosis:-

  • Pathogen: EBV infects B lymphocytes. 

  • Incubation period: Approximately 4 to 6 weeks.

  • Symptoms: Sore throat, fever, swollen spleen, enlarged lymph. 

Viral Pneumonia:- 

  • Pathogen: Respiratory viruses 

  • Incubation period: 2 to 5 days

  • Symptoms: clammy skin, chills, fever dehydration,  shallow breathing,  loss of appetite, fast breathing, coughing,  fast heart rate.

Human Papillomavirus (HPV):- 

  • Pathogen: Warts

  • Incubation period: 2 to 3 months

  • Symptoms: Genital warts, flat warts, common warts, cervical cancer, plantar warts.