Tuberculosis is a common and an infectious disease which is caused by bacteria called "Mycobacterium tuberculosis". It was first isolated in 1882 by a German physician named "Robert Koch" who received the Nobel Prize for this discovery. Tuberculosis most commonly attacks the lungs but can also affect the central nervous system, the lymphatic system, the circulatory system, the genitourinary system, bones, joints and even the skin.

Types of Tuberculosis:

1. Active Tuberculosis: Active TB means the bacteria are active in the body. The immune system is unable to stop these bacteria from causing illness. People with active TB in their lungs can pass the bacteria on to anyone they come into close contact with. When a person with active TB coughs, sneezes or spits, people nearby may breathe in the tuberculosis bacteria and become infected.
2. Inactive Tuberculosis: Inactive TB infection is also called latent TB. If a person has latent TB, it means their body has been able to successfully fight the bacteria and stop them from causing illness. People who have latent TB do not feel sick, do not have symptoms and cannot spread tuberculosis.

In the People who have HIV, the inactive TB may become active TB if their immune system becomes weakened.

Causes
A person can become infected with tuberculosis bacteria when he or she inhales minute particles of infected sputum from the air. The bacteria get into the air when someone who has a tuberculosis lung infection coughs, sneezes, shouts, or spits (which is common in some cultures).

Tuberculosis is a serious health problem in its own right but it is also the most likely cause of death for HIV positive people. Like HIV, tuberculosis has had an uneven impact around the world.  

Risk factors of Tuberculosis are:

• Aging
• Alcoholism
• Crowded living conditions
• Diseases that weaken the immune system
• Health care workers
• HIV infection
• Homelessness
• Low socioeconomic status
• Malnutrition
• Migration from a country with a high number of cases
• Nursing Homes
• Unhealthy Immune System
• Use of drugs for Arthritis

Signs & Symptoms
The primary stage of the tuberculosis may be symptom-free, or the individual may experience a flu-like illness. TB mainly affects lungs and coughing is often the only indication of infection initially. Signs and symptoms of Tuberculosis include:

• A cough lasting for more than 2-3 weeks
• Chest Pain
• Chills
• Discolored or bloody sputum
• Fatigue
• Loss of appetite
• Night sweats
• Pain with breathing
• Severe Headache
• Shortness of breath
• Slight fever
• Tiredness or weakness
• Weight loss

Diagnosis
A complete medical diagnosis for TB includes a review of complete medical history, physical examination of patient, a tuberculin skin test, a chest X-ray, and microbiologic smears and cultures. Tuberculosis can be diagnosed by many ways:

• Injection of Protein: By injecting a protein found in TB bacteria into the skin of an arm. If the skin reacts by swelling then the person is probably infected with tuberculosis.
• X-ray: Diagnosis of tuberculosis in the lungs may be made using an X-ray
• Sputum test: Sample of sputum is test in laboratory to diagnos the TB.
• Bacteria: A culture of TB bacteria can also be grown in a laboratory. However, this requires specialised and costly equipment and can take six to eight weeks to produce a result.

Preventions
Preventive measures include strict standards for ventilation, air filtration etc.

• A vaccine, BCG, is available and has been of some benefit in preventing TB
• Covering of mouth by a mask is helpful in prevention from TB
• Exercise regularly to keep your immune system
• Get adequate amounts of sleep
• Get tested regularly. Experts advise getting a skin test annually
• Keep your immune system healthy.
• Make sure you eat plenty of healthy foods
• A drug called Isoniazid (INH) can be used as a preventative therapy for those who are at high risk of becoming infected with tuberculosis.
• The WHO recommends that HIV positive people who have latent TB should be offered isoniazid preventive therapy as needed.

The resulting drug-resistant strains are much more deadly and difficult to treat.

Treatments

• Active TB disease can almost always be cured with a combination of antibiotics.
  Avoid nutrient deficiencies and imbalances.
• If someone is believed to have been in contact with another person who has TB, preventive antibiotic treatment may have to be given.
• Streptomycin, a drug that is given by injection, may be used as well, particularly when the disease is extensive
• The patient should take his/her pills under the guidance of someone who can supervise the therapy. The approach is called DOTS (Directly Observed Treatment, Short Course).
• Surgery on the lungs may be indicated to help cure TB when medication has failed

If the patient develops any side effects from medications such as itching, change in color of skin, tiredness, or excessive fatigue and you must call your doctor immediately.