Colds and Flu

Immune System

Cold: a cold is the term we use to describe an acute inflammation of the mucous membranes of the respiratory passages, especially the nose and throat, thought to be caused by several different viruses. The viral infection causes a stuffed up / runny nose, sneezing, a sore throat, and often a dry cough. Usually the lymph glands in the neck will become tender and swollen. Colds cause different symptoms in different people, even if it is the same virus. If there is a fever with a cold, it is usually manageable.

Influenza: influenza (the flu) is an acute, contagious, infectious disease, caused by any of a specific group of viruses and characterized by inflammation of the respiratory tract, fever and muscular pain. The flu exhibits similar symptoms to a cold, but it is much more severe than colds, and will cause high fevers, chills and a feeling of total exhaustion; the whole body aches. The viruses that cause the flu tend to attack the upper respiratory tract with a combination of symptoms – a sore throat, dry cough, and a runny nose. In stomach flu, nausea and vomiting are typical. These are all symptoms of our body’s immune system attempting to rid the body of the viral invader. Although the flu is usually gone within a week or so, the body’s recuperating time is longer because of the strain put on the bronchial tubes and circulatory system.

Causes: flu is caused by 3 principal types of influenza viruses. The most common strain is influenza A, and is responsible for the most serious flu epidemics. About every three years, there are widespread epidemics of Influenza A, and every 30 to 40 years, there are more serious worldwide epidemics, called pandemics. 

Influenza B also causes epidemics about every five years, but most cases are relatively mild. The influenza C virus is always present, but it only occasionally causes a few local outbreaks of mild flu.

Mode of Transmission:

Flu passes from one person to another through droplets in the air. When a person with flu coughs or sneezes, millions of viral particles are sprayed into the air. When the flu virus is inhaled, it quickly starts to multiply. The virus spreads so easily that in only a few days a local epidemic may develop.

Manifestations:

After about 48 hours of incubation, a person with the flu virus suddenly begins to feel very sick. The first symptoms include a fever of 102 to 103 degrees F, shaking chills, headache, and a backache and leg pains. Fatigue and weakness are common. The respiratory symptoms – a runny or stuffy nose, sore throat, and dry, hacking couch – are mild at first, but worsen in the next few days.

Natural course:

The fever usually lasts for two or three days, but the other symptoms may last for a week or ten days. The fatigue and general malaise often last even longer.
Most healthy people recover fully in a few weeks, and are then immune to the particular strain of the flu virus that affected them. Complications such as pneumonia or secondary bacterial respiratory infections are most common in the elderly or people weakened by other diseases.

SYMPTOMS:

• Sudden onset of fever and chills
• Sore throat and runny or stuffy nose
• Dry cough that produces sputum after a few days
• Headache and generalized aches, especially in the back and legs
• Lingering fatigue and general malaise