Dr. Katz gives himself a flu shot...

Flu symptoms

What is influenza?

Influenza (also called flu) is a viral infection of the nose, throat, trachea, and bronchi (air passages). Outbreaks of flu occur almost every year, usually in winter.

Flu viruses cause more severe symptoms and can cause more severe medical problems than cold viruses. The elderly, people whose immune systems are impaired, and people with chronic medical problems are particularly at risk for more severe flu symptoms or complications.

How does it occur?

The flu virus is almost always spread from person to person by droplets that are coughed or sneezed into the air. It can also be spread by the hands of an infected person who has touched their mouth or nose.

What are the symptoms?

Influenza tends to start suddenly. You may feel fine one hour and have a high fever the next. The usual first symptoms are:

Symptoms soon to follow may include:

How is it diagnosed?

Influenza can usually be diagnosed from your symptoms. Your health care provider may examine you to rule out other types of infection, such as strep throat and sinusitis.

How is it treated?

Usually you will recognize the symptoms and can manage them at home. It is a good idea to speak to your health care provider if you have symptoms of the flu and:

To take care of yourself at home:

There are medicines your ZoomCare physician can prescribe that can make flu symptoms less severe. They may also help the symptoms not last as long. Examples of these drugs are amantadine (Symadine or Symmetrel), rimantadine (Flumadine), zanamivir (Relenza), and oseltamivir (Tamiflu). These flu medicines are available as tablets or nasal sprays. They must be started within the first 48 hours of illness to be effective. Usually they need to be taken only a few days. A common side effect of the tablets is lightheadedness or dizziness.

How long will the effects last?

Flu symptoms usually last 3 to 7 days. They often start improving gradually after the first 2 days or so.

Infection with the flu virus often leads to other infections, such as ear, sinus, and bronchial infections. Pneumonia can also occur as a result of the flu. It can be caused by the flu virus itself or by bacteria invading lung tissues that have been damaged by the virus. Pneumonia is a common cause of death in people over the age of 65 and often occurs during and after flu outbreaks.

An unusual complication of flu is Reye's syndrome, which usually occurs in children and adolescents and rarely occurs in adults. Reye's syndrome is not well understood but it involves failure of the liver and brain swelling, which together can lead to coma and sometimes death. A link has been shown between the use of aspirin during influenza illness and the development of Reye's syndrome. For this reason it is best to avoid taking aspirin when you have the flu.

What can I do to prevent influenza?

Flu shots are usually about 70% effective in preventing flu. Because the flu virus strain varies from year to year, you need to get a new flu shot each year. October is the best time to get vaccinated, but you can still get vaccinated in November and later. Flu season can begin as early as October and last as late as May. Flu seasons can vary from region to region. If you are at high risk from infection and plan to travel to an area where you might be exposed to the flu, make sure you have an up-to-date flu shot before you go on your trip.

A new alternative to flu shots is FluMist. It is a nasal spray form of the vaccine for healthy adults under 50 years of age. It costs more than the shot. As with flu shots, you will need a new dose of FluMist every year. Pregnant women cannot take the nasal spray.

If a flu outbreak has begun and you have not had the flu vaccine and need some protection, your health care provider may prescribe medicine that can decrease your chances of getting the flu during the outbreak. You will need to take these medicines for at least 2 weeks after you are vaccinated or, if you don't get the vaccine, until the flu outbreak has left your community, which may be several weeks. If you do get the flu, the medicines can make your symptoms less severe.

The simplest, oldest method of avoiding spread of infection is frequent hand washing, preferably with antibacterial soap from a sanitary dispenser. It is also a good practice not to eat in or near your workplace. Your hands or food might be contaminated with the virus particles from co-workers, customers, or schoolchildren, depending on your place of work.