LFT and KFT (Liver Function Test & Kidney Function Test)

Gamma-Glutamyl Transferase (GGT) is an enzyme found in various organs, with the highest concentration in the liver. Usually, this enzyme is present in low levels in the blood. However, when there is liver damage or disease, GGT is released into the bloodstream, causing an increase in GGT levels. In addition to the liver, GGT can also be elevated in conditions affecting the bile ducts or the pancreas. It is usually, the first liver enzyme to rise in the blood when there is any damage or obstruction in the bile duct, making it one of the most sensitive liver enzyme tests for detecting bile duct problems.

An SGPT test measures the amount of ALT or SGPT enzyme in your blood. ALT is most abundantly found in the liver but is also present in smaller amounts in other organs like the kidneys, heart, and muscles. Its primary function is to convert food into energy. It also speeds up chemical reactions in the body. These chemical reactions include the production of bile and substances that help your blood clot, break down food and toxins, and fight off an infection.

Elevated levels of ALT in the blood may indicate liver damage or injury. When the liver cells are damaged, they release ALT into the bloodstream, causing an increase in ALT levels. Therefore, the SGPT/ALT test is primarily used to assess the liver's health and to detect liver-related problems such as hepatitis, fatty liver disease, cirrhosis, or other liver disorders.

An Alkaline Phosphatase (ALP) test measures the quantity of ALP enzyme present throughout the body. The main sources of this enzyme are the liver and bones. It exists in different forms depending on where it originates, such as liver ALP, bone ALP, and intestinal ALP. In the liver, it is found on the edges of the cells that join together to form bile ducts. 

ALP levels can be increased during pregnancy as it is found in the placenta of pregnant women. It is also higher in children because their bones are in the growth phase. ALP is often high during growth spurts (a short period when an individual experiences quick physical growth in height and body weight).

An SGOT test measures the levels of serum glutamic-oxaloacetic transaminase (SGOT), also known as aspartate aminotransferase (AST), an enzyme produced by the liver. SGOT is present in most body cells, most abundantly in the liver and heart. The primary function of this enzyme is to convert food into glycogen (a form of glucose), which is stored in the cells, primarily the liver. The body uses this glycogen to generate energy for various body functions.

The Protein Total, Serum test measures the amount of proteins in the body. Proteins are known as the building blocks of all cells and tissues. They play a crucial role in the growth and development of most of your organs and in making enzymes and hormones. There are two types of proteins found in the body, namely albumin and globulin. About 60% of the total protein is made up of albumin, which is produced by the liver. It helps to carry small molecules such as hormones, minerals, and medicines throughout the body. It also serves as a source of amino acids for tissue metabolism. On the other hand, globulin is a group of proteins that are made by the liver and the immune system. They play an important role in liver functioning, blood clotting, and fighting off infections.

This further contains

• Albumin/Globulin Ratio, Serum
• Protein Total
• Serum Albumin
• Globulin, Serum

The Bilirubin (Total, Direct and Indirect) test measures the level of three forms of bilirubin such as total bilirubin, direct (conjugated bilirubin), and indirect (unconjugated) bilirubin in the blood. Total bilirubin represents the sum of direct and indirect bilirubin. Direct bilirubin is the water-soluble form of bilirubin that has been processed by the liver via a conjugation process with glucuronic acid and is ready to be excreted into the bile ducts and ultimately into the intestines. Indirect bilirubin is the water-insoluble form of bilirubin that has not yet been processed by the liver and is bound to albumin in the blood. It is formed in the spleen and liver during the breakdown of hemoglobin from old or damaged red blood cells and cannot be excreted directly by the liver. Instead, it is transported to the liver, where it undergoes conjugation to become direct bilirubin. 

Getting tested with the Bilirubin (Total, Direct and Indirect) test provides valuable information into various aspects of liver function, bile duct health, and the body’s ability to break down and eliminate bilirubin.

This further contains

• Bilirubin Direct
• Bilirubin Total
• Bilirubin Indirect

The Serum Creatinine test measures the level of creatinine in the blood. Creatinine is a byproduct of muscles’ wear and tear during energy production. The kidneys remove it from the body by filtering it from the blood and releasing it into the urine. Therefore, blood creatinine levels indicate how well the kidneys are functioning in filtering and removing waste products from the blood. Generally, higher creatinine levels in the blood may indicate reduced kidney function, while lower levels may suggest decreased muscle mass.

An Uric Acid test determines the level of uric acid in your body. Uric acid is a nitrogenous compound produced by the metabolic breakdown of purine. Purines are present as nitrogenous bases in the DNA and are also found in food like red meat and seafood.

Most uric acid dissolves in the blood and goes into your kidneys. From there, it passes through your body via the urine. Decreased elimination of uric acid is often a result of impaired kidney function due to kidney disease. In many cases, the exact cause of excess uric acid is unknown. Doctors seldom need to test for low levels of uric acid.

The Blood Urea Nitrogen test measures the levels of urea nitrogen in the blood. Blood urea is a waste product that is formed in the liver when you eat food and the protein is metabolized into amino acids. This process leads to the production of ammonia that is further converted into urea. Both ammonia and urea are nitrogenous compounds. Your liver releases urea into the blood which is then carried out to the kidneys. In the kidneys, urea is filtered from the blood and flushed out of the body via urine. This is a continuous process, so a small amount of urea nitrogen always remains in the blood.

In the case of a kidney or liver disease, there is a change in the amount of urea present in the blood. If your liver produces urea in an increased amount or if there is any problem in kidney functioning, there might be difficulty in filtering out the waste products from the blood, which can result in increased urea levels in the blood.

The BUN/Creatinine Ratio test helps compare the levels of blood urea nitrogen to that of creatinine in your body. Urea is a waste product that is formed in the liver when you eat protein, which is then metabolized into amino acids. This process leads to the production of ammonia that is further converted into urea. Later, the urea is passed out of your body through the urine. On the other hand, creatinine is a byproduct produced by muscles during energy production. Therefore, the more muscle you have, the more creatinine your body produces. The kidneys remove both the urea and creatinine via urine, and this test determines how well your kidneys are functioning.

The Blood Urea test measures the level of urea in the blood. Urea is a byproduct of protein metabolism. Proteins you consume in your diet are digested and converted into amino acids, which are then utilized by the body. This metabolic process produces a toxic byproduct known as ammonia. Ammonia is then rapidly converted into urea by your liver. Urea is comparatively less toxic than ammonia and is transported to the kidneys via the blood. The kidneys then filter it out through the urine. This process continues and the body keeps producing and eliminating urea, maintaining its low and steady levels in the blood.

The Sodium test measures the amount of sodium in your body. Sodium is present in all body fluids and is found in the highest concentration in the extracellular fluid. The body absorbs the required amount of sodium through dietary salts, and the kidneys eliminate the remaining sodium. The body keeps your blood sodium within a regular and steady range by following three mechanisms:

• By producing hormones that control the elimination of sodium through urine, such as natriuretic peptides and aldosterone.

• By producing hormones that prevent water loss, such as antidiuretic hormone (ADH).

• By controlling thirst (an increase in blood sodium level can make you thirsty and cause you to drink water, returning your sodium to normal).

These mechanisms regulate the amount of water and sodium in the body and control blood pressure by keeping the amount of water in check. When the sodium level in the blood changes, the water content in your body changes. These changes can be associated with dehydration, edema, and changes in blood pressure.

The Chloride test measures the amount of chloride in your body. Chloride is present in all body fluids and is found in the highest concentration in the blood and extracellular fluid (fluid present outside the cells). The body gets most of the chloride through dietary salt (sodium chloride or NaCl) and a small amount through other food items. The required amount of chloride is absorbed in the body and the excess amount is excreted by the kidneys through urine. When the chloride is combined with sodium it is mostly found in nature as salt. Chloride generally increases or decreases in direct relationship to sodium but may also change without any changes in sodium levels when there are problems with the body's pH. Usually, the normal blood chloride level remains steady with a slight fall after meals (because the stomach produces hydrochloric acid using chloride from the blood after we eat food).

The Potassium test measures the levels of potassium in your body. Potassium is one of the key electrolytes that helps in the functioning of the kidneys, heart, nerves, and muscles. It also balances the effect of sodium and helps keep your blood pressure normal. The body absorbs the required amount of potassium from the dietary sources and eliminates the remaining quantity through urine. Potassium level is typically maintained by the hormone aldosterone. Aldosterone acts on the nephrons present in the kidneys and activates the sodium-potassium pump that helps the body reabsorb sodium and excrete potassium. This aids in maintaining a regular and steady potassium level in the blood.