What Are the Major Organs of the Body? 9 Vital Organs

Medically Reviewed on 12/30/2021
What Are the Major Organs of the Body
The major organs of the body include the heart, brain, lungs, kidneys, liver, skin, bones, adrenal glands, and hematopoietic system

There are about 78 organs in the human body, all of which coordinate with each other to ensure that the body functions properly. While each organ serves a specific function and is important to overall health, some organs are vital for survival.

9 major vital organs

  1. Heart: The heart is the main organ of the cardiovascular system. It is the size of a fist and is located just behind and slightly left of the breastbone. It pumps blood through a network of arteries and veins throughout the body.
  2. Brain: The brain is one of the most complex organs of the body, made up of more than 100 billion nerves that help other organs communicate with each other..
  3. Lungs: The lungs are a pair of spongy, air-filled organs that are part of the respiratory system and located on either side of the chest (thorax).
  4. Kidneys: The kidneys are a pair of bean-shaped organs that are part of the urinary system and located on either side of the spine, below the ribs, and deep in the abdomen.
  5. Liver: The liver is the largest internal solid organ in the body located on the right side of the abdomen. It has multiple functions, the most important being energy production and metabolism.
  6. Skin: The skin acts as a protective barrier against bacteria or fungi from entering the body. It maintains body temperature and pH balance.
  7. Bones: Bones not only support organs and muscles but also play a major role in calcium metabolism in the body.
  8. Adrenal glands: These glands secrete hormones that help the body deal with stress. If these organs fail, the body may go into a potentially fatal shock.
  9. Hematopoietic system: Blood consists of red and white cells and platelets. If this organ system fails, it can lead to severe bleeding or death from severe infections.

Functions of major organs and conditions that can damage them

Table 1: Organ functions and damaging conditions
Organ Functions Conditions that may damage the organ Possible symptoms of organ damage
Brain Controls all other organs and their functioning
  • Meningitis
  • Stroke
  • Brain tumor
  • Metabolic disorders such as diabetic ketoacidosis
  • Persistent headaches
  • Extreme mental or physical fatigue
  • Paralysis
  • Weakness
  • Tremors
  • Seizures
  • Sensitivity to light
  • Problems with thinking
  • Problems in short-term or long-term memory
  • Dizziness
  • Nausea or vomiting (early phase)
Heart Pumps blood to deliver a continuous supply of oxygen and other nutrients to other organs
  • Hypertension
  • High cholesterol levels
  • Diabetes
  • Myocardial infarction (heart attack)
  • Congenital heart conditions such as mitral valve stenosis
  • Shortness of breath with activity or when lying down
  • Swelling in the legs, ankles, and feet
  • Rapid or irregular heartbeat
  • Decreased ability to exercise
  • Persistent cough or wheezing with white or pink blood-tinged mucus
  • Swelling of the abdomen
  • Chest pain
  • Fatigue
  • Weakness
Lungs Helps oxygen breathed air to enter the red cells in the blood
  • Pneumonia
  • Tuberculosis
  • Asthma
  • Bronchitis
  • COVID-19
  • Lung cancer
  • Trouble breathing
  • Shortness of breath
  • Chest pain or discomfort when inhaling or exhaling
  • Feeling of not getting enough air
  • Decreased ability to exercise
  • Persistent cough
  • Coughing up blood or mucus
Kidneys Filters blood and removes waste products through urine
  • Polycystic kidney
  • Cancer
  • Hydronephrosis
  • Hydroureter
  • Chronic kidney disease
  • Decreased urine output
  • Bloody urine
  • Foamy urine
  • Swelling in the legs, ankles, or feet caused by fluid retention
  • Poor appetite
  • Muscle cramps
  • Shortness of breath
  • Fatigue
  • Confusion
  • Nausea
  • Weakness
  • Dry and itchy skin
Liver Removes waste products and foreign substances from the blood, regulates blood sugar levels, and produces essential nutrients such as albumin
  • Nonalcoholic steatohepatitis
  • Liver cirrhosis stage III
  • Hepatocellular carcinoma (liver cancer)
  • Polycystic liver
  • Chronic hepatitis A, B, and C
  • Abdominal pain (especially on the right side)
  • Easy bruising
  • Changes in the color of urine or stool
  • Fatigue
  • Nausea or vomiting
  • Swelling in the arms or legs


The 14 Most Common Causes of Fatigue See Slideshow

What is organ transplantation?

Organ transplantation may be the last resort of treatment for extensive organ damage. It is a life-saving surgery that is currently available only for the following organs:

  • Liver
  • Kidney
  • Heart
  • Lung
  • Pancreas
  • Intestine
Table 2: Duration in which the organ should be retrieved from a dead body for transplantation
Organ Duration
Heart 4-6 hours
Lungs 4-6 hours
Kidneys 24-36 hours
Liver 8-12 hours

After organ transplantation, patients must take immunosuppressants for the rest of their lives to avoid rejection of the organ that has been transplanted.

Medically Reviewed on 12/30/2021
Image Source: iStock Images

Organ Transplantation. https://medlineplus.gov/organtransplantation.html

What is the Time Frame for Transplanting Organs? https://www.donoralliance.org/newsroom/donation-essentials/what-is-the-time-frame-for-transplanting-organs/