ALT Blood Tests: What Is It?

What is an ALT blood test?

An alanine transaminase (ALT) blood test measures the level of the ALT enzyme in your blood. ALT is primarily found in liver cells and is released into the bloodstream when the liver is damaged.

Usually, you will have low levels of ALT, but liver issues may cause your liver cells to release more of it into your bloodstream. The ALT blood test is often part of a group of liver function tests and is mainly used to diagnose and monitor liver disease.

However, it is also particularly useful in identifying conditions such as hepatitis, cirrhosis, and fatty liver disease. Overall, an ALT blood test helps your healthcare providers detect liver damage or injury even before symptoms appear. 

Why do I need an ALT blood test?

Your doctor may recommend an ALT blood test as part of a routine checkup or if you:

• Show symptoms of liver disease (e.g., jaundice, abdominal pain, nausea)

• Have risk factors for liver damage (e.g., alcohol consumption, obesity, diabetes)

• Have been exposed to hepatitis viruses

• Take medications known to affect liver function

If you have any family history of liver disease, you may also want to consider taking an ALT blood test.

Will I need to do anything to prepare for the test?

Generally, no special preparation is needed for an ALT blood test. Your doctor, however, might suggest that you:

1. Fast for a few hours before the test. (Usually, there is no need to fast if you're only getting an ALT blood test, but if the ALT test is part of a comprehensive metabolic panel (CMP), you will need to fast for 10 to 12 hours before the CMP blood test.)

2. Tell them about any medications or dietary supplements you are currently taking. There is no need to stop taking any medications unless your doctor tells you to.

3. Avoid intense exercise before the test, as it can affect results

Please note that your doctor will provide any additional instructions, if needed, when ordering the bloodwork.

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations and tailored advice, please consult a specialist at Thomson Medical. Book an appointment with Thomson Medical today.

What happens during an ALT blood test?

The ALT blood test is a simple procedure:

1. A healthcare professional will clean an area on your arm with an antiseptic.

2. They will insert a small needle into a vein to draw blood.

3. The blood sample is collected in a vial or tube.

4. The needle is removed, and the puncture site is covered with a bandage.

The entire process usually takes only a few minutes, and you may feel a little sting when the needle goes through your skin.

What is the range for normal ALT levels?

Normal ALT levels typically range from 4 to 36 U/L (units per litre). Elevated ALT levels often indicate liver damage or disease. Conditions that can cause increased ALT levels include:

• Hepatitis

• Cirrhosis

• Fatty liver disease

• Liver cancer

• Certain medications, such as cholesterol or pain medicines

• Mononucleosis

• Pancreatitis

• Other liver diseases

It's crucial to understand that ALT levels alone don't offer a comprehensive view of liver health. Liver function tests measure different proteins, substances, and enzymes that show how healthy your liver is, and your doctor will usually compare your ALT results with those of other liver tests to evaluate your overall liver health and decide if you need more tests for further evaluation.

Are there any risks to the test?

The ALT blood test is generally safe with minimal risks. Some people may experience:

• Slight pain or bruising at the needle site

• Dizziness or lightheadedness

• In rare cases, excessive bleeding or infection

If you have any concerns about the test, discuss them with your healthcare provider.

Remember, regular liver function tests, including ALT, can help detect liver problems early, allowing for more effective treatment and management of liver conditions.

Should I seek treatment if my ALT levels are high?

There is no specific medical treatment for high ALT levels. However, if treatment is needed, it will depend on what is causing the increase. For most cases of high ALT levels, the treatment will involve lifestyle changes, such as reducing alcohol intake, incorporating more regular exercise into your daily routine, and having a healthier diet.

Overall, it is best to consult your healthcare provider if you require an ALT blood test, especially if you have any underlying medical condition that may affect your liver's health.

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations and tailored advice, please consult a specialist at Thomson Medical. Book an appointment with Thomson Medical today.

FAQ

What does it mean if your ALT is high?

High levels of ALT in your blood may be a sign of a liver injury or disease. Some types of liver disease cause high ALT levels even before you have symptoms of the disease. So, an ALT blood test may help diagnose certain liver diseases early, when they may be easier to treat

What is the alarming level of ALT?

A result of >100 IU/l on the ALT test clearly shows severe liver disease. A slightly higher result (30–100 IU/l) is usually linked to taking medicine (like statins) or drinking alcohol, while lower levels (<50 IU/l) are thought to be normal for test results.

How do I get my ALT levels down?

Anyone with liver damage or significantly high levels will need medical attention to prevent complications and long-term problems.

However, some at-home tips to bring your ALT levels down include:

• Exercising regularly.

• Managing weight.

• Increasing folic acid intake.

• Making dietary changes by eating more leafy greens such as kale, spinach, and Brussels sprouts and healthy proteins such as fish, chicken, lentils, edamame, tofu, and nuts

• Managing cholesterol.

• Take care with medications or supplements.

What is the normal ALT range?

The normal ALT value for people without risk factors for liver disease ranges from 29 to 33 international units per litre (IU/L) for males and 19 to 25 IU/L for females. This value can vary depending on the lab.

What is the ALT level for fatty liver?

The cutoff value of ALT for the diagnosis of this disease is estimated to be 25 U/L in men and 17 U/L in women. For the BAAT score, a normal range of ALT is considered between 1 and 19.

What happens if ALT is low?

Low ALT levels may be a sign of increased frailty and a higher risk of death in older people and people with chronic kidney disease (CKD) who are on haemodialysis.

What are the symptoms of liver damage?

Liver damage or liver disease may not always manifest symptoms. If there are symptoms of liver disease, they may include:

• Jaundice, which is the yellowing of the skin and the whites of the eyes. This symptom might be harder to see on black or brown skin.

• Belly pain and swelling.

• Swelling in the legs and ankles.

• Itchy skin.

• Dark urine.

• Pale stool.

• Constant tiredness.

• Nausea or vomiting.

• Loss of appetite.

• Bruising easily.

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations and tailored advice, please consult a specialist at Thomson Medical. Book an appointment with Thomson Medical today.