Influenza or the "Flu" is a common infection of the lungs and breathing passages, as well as other parts of the body. The name influenza comes from the Italian word "influenza" which means "influence" and in Latin it is known as influentia. Influenza affects millions of people, anyone can get the flu, but young children, older adults, people with weakened immune systems and those with chronic illnesses are especially get affected by this virus.

Compared with most other viral respiratory infections, such as the common cold, influenza infection often causes a more severe illness which has a mortality rate of about 0.1% of people who are infected with the virus. The incubation period of influenza is one to four days long, with an infection period lasting from 3 to 7 days. Most deaths that involve the flu are attributed to secondary bacterial infections that appear after damage to the upper respiratory tract.

Influenza virus is classified into different types i.e. A, B, and C

• Type A is the most common and usually causes the most serious epidemics.
• Type B can cause epidemics, but the disease it produces generally is milder than that caused by type A.
• Type C viruses never have been connected with a large epidemic.

Causes
Influenza is caused by a virus in the human body. It spreads when infected persons cough, sneeze, or even talk around others. The flu spreads quickly anywhere people gather like schools, child-care centers, offices, nursing homes, buses, conferences and cruises when someone who's infected with the influenza virus coughs or sneezes.

• People can get the virus simply by touching a surface like a telephone or doorknob that has already been infected by a touch from infected person.
• The viruses can pass through the infected air and enter your body through your nose or mouth while breathing.
• Virus can also pass on to the persons if they have touched a contaminated surface, from their hand to their nose or mouth. 

Signs & Symptoms
Symptoms usually appear in a person 1 to 4 days after being exposed. The main symptoms of influenza are:

• Burning Eyes
• Chills & Sweats
• Depression
• Diarrhea and vomiting in children
• Dizziness
• Dry Cough
• Fever & Headache
• Loss of Appetite
• Muscle Aches
• Nausea , Runny Nose , Sore Throat
• Sweating
• Tiredness & Weakness
• Typically, the fever begins to decline on the second or third day of the illness.

Diagnosis
Doctors can easily diagnose the disease simply by examining a patient.

• A doctor will diagnose the flu based on its symptoms like fever, chills, headaches, cough and body aches.
• Some tests are also available to identify the virus, but these tests are seldom needed for the purpose of diagnosis.
• Some tests may be necessary to diagnose secondary infections. For example, a doctor may take a throat culture to identify a throat infection.

Preventions
There are the following ways by which you can prevent yourself from Influenza:

• Get balance diet, and add more fruits and vegetables, pulses and whole grains in your diet.
• Prevent yourself from traveling in crowded places, especially in flu season.
  Proper sanitation and hygiene is also required
• Regular exercise is very beneficial, although it can not prevent you from getting virus but it makes your body so strong that can fight with virus.
• The main way to keep from getting flu is to get a yearly flu vaccine. You can get the vaccine at your doctor's office or a local clinic, and in many communities at workplaces, supermarkets, and drugstores. You must get the vaccine every year because it changes.
• Wash your hands properly and turn off the faucet with paper napkin

Treatments

• Patient needs plenty of bed rest and lots of fluids to treat the flu. But in some cases, your doctor may prescribe an antiviral medication.
• Steam vaporizer can make breathing easier. Painkillers can be helpful in relieving the aches and pains of the flu.
• Warm-water enema should be taken daily during the first three to five days of the treatment.
• Children less than 10 years of age should not be given aspirin; Aspirin has been shown to cause a rare condition known as Reye's syndrome, which can be fatal.
• During the course of the fever, the natural way of reducing temperature is by means of cold body packs, which should be applied several times a day.
• Patients suffering from flu do not feel hungry. So, they should be encouraged to eat as normally as possible.
• Patients should keep in mind that over activity can cause a return of the infection or secondary infections, so, take rest as much as possible.

Alternative Treatments
Various types of alternative treatments have been recommended for the treatment of influenza. But in most of the cases the success of these treatments has little or no scientific evidence available. Some of the alternative treatments include:

• Acupuncture and Acupressure: Practitioners believe that these two techniques can stimulate natural resistance, relieve nasal congestion and headaches, reduce fever, and soothe coughs.
• Aromatherapy: Aromatherapy is recommended for relieving the flu. Some of the treatment in aromatherapy are as follows:
  • Gargling daily with one drop each of tea tree oil and lemon in a glass of warm water.
  • Two drops of tea tree oil in a hot bath may help ease some symptoms.
  • Few drops of the oils of eucalyptus or peppermint can be added to a Steam vaporizer. They may help clear chest and nasal congestion. 

• Homeopathy: In homeopathic treatment a variety of herbs are recommended for the treatment of the flu. These include
  • Gelsemium: treats chills, headache, and nasal congestion;
  • Bryonia: treats muscle aches, headaches, and dry cough
  • Poison ivy: treats restlessness, chills, hoarseness, and achy joints. 

• Hydrotherapy: Taking a hot bath may help a person recover from the flu more quickly: The higher a person's body temperature, the more quickly the virus is likely to die.
• Vitamins: Large doses of vitamin C can be helpful in preventing the flu. Doctors suggest increasing the amount of vitamin C once a flu infection has started.