What this article covers
- What are ALT and AST?
- How to read your result
- What does the AST to ALT ratio tell you?
- Fatty liver: the most common cause across the region
- Viral hepatitis and other causes
- Medicines and supplements: the cause that is often forgotten
- What happens after an abnormal enzyme result
- Liver health and the bigger picture
What are ALT and AST?
ALT stands for Alanine Aminotransferase, also written as SGPT in older reports. It is an enzyme found in high concentrations inside liver cells. When those cells are damaged for any reason, ALT leaks into the bloodstream and its level in a blood test rises. This makes ALT the most liver-specific of the routine liver enzymes and the one most clinicians watch first when liver disease is suspected.
AST stands for Aspartate Aminotransferase, also written as SGOT. It is present in the liver but also in heart muscle, skeletal muscle and the kidneys. A rise in AST alone, without a corresponding rise in ALT, can indicate muscle strain, a heart attack or a muscle disorder rather than liver disease. This is why AST should never be interpreted in isolation from the clinical picture.
Neither enzyme requires fasting before testing, and both are measured in international units per litre (U/L). Reference ranges vary slightly between laboratories, between the sexes and with age, so always read the range printed on your own report rather than using a generic number. Men typically have a slightly higher upper limit of normal than women for ALT.
ALT reference range for adults
Source: AMAGE clinical practice guidelines for MAFLD, Annals of hepatology, 2026
How to read your result
The normal range for ALT at most laboratories is approximately 7 to 56 U/L for adults, with men having a slightly higher upper limit than women. AST is usually in a similar range of 10 to 40 U/L, with variation between labs. The exact numbers printed on your report are the ones that matter, not a figure you find elsewhere.
What matters to your doctor is not just the absolute number but how many times the upper limit of normal it has reached. A rise to two or three times the upper limit is classified as mild to moderate and warrants investigation and follow-up. A rise beyond ten times the upper limit is described as acute and severe, and needs urgent assessment regardless of symptoms.
Enzymes can rise transiently after strenuous exercise, after a very fatty meal or in response to certain short-term medicines. If a raised result is unexpected and there is no obvious cause, your doctor may repeat the test after two to four weeks while avoiding the potential triggers, before pursuing a more extensive workup.
What does the AST to ALT ratio tell you?
The ratio of AST to ALT, written AST/ALT, adds diagnostic information on top of the absolute numbers. In fatty liver disease, viral hepatitis and autoimmune hepatitis, ALT is usually higher than AST, which means the ratio is below 1. This is the common pattern for most non-alcoholic liver conditions.
A 2024 study in Frontiers in Endocrinology demonstrated that an elevated ALT/AST ratio correlates with increased risk and severity of metabolic dysfunction-associated fatty liver disease, and that this ratio can serve as an early screening indicator even before ultrasound imaging is available.
When the AST/ALT ratio exceeds 2, this is a classic pointer towards alcoholic liver disease, or in some cases towards advanced cirrhosis from any cause. A 2021 study in BMC Gastroenterology, which compared this ratio against FibroScan results in patients from southern Iran, confirmed its diagnostic value in distinguishing fibrosis stages in fatty liver disease. Your doctor will use the ratio alongside your history, symptoms and other tests to narrow the possibilities.
Fatty liver: the most common cause across the region
Metabolic dysfunction-associated fatty liver disease, now abbreviated as MAFLD or MASLD, is the accumulation of fat inside liver cells without significant alcohol consumption. It is closely linked to obesity, insulin resistance, type 2 diabetes and elevated blood fats. It is by far the most common cause of a mildly or moderately raised ALT across the Gulf, Egypt and the wider Arab world.
A 2021 consensus statement from Middle East and North African liver disease experts, published in the Lancet Gastroenterology and Hepatology, documented that MAFLD prevalence in the region has reached epidemic levels, with studies in some countries finding rates above 30 to 40 percent of adults. The drivers include the rapid rise in obesity rates and the dramatic increase in consumption of sugar-sweetened drinks over the past two decades.
The good news is that early fatty liver is fully reversible. Losing 5 to 10 percent of body weight has been shown in multiple trials to reduce liver enzyme levels and improve the appearance of the liver on ultrasound. The 2026 AMAGE clinical guidelines, developed specifically for the African Middle East region, confirm that lifestyle intervention remains the most effective first-line treatment and should precede any pharmacological approach.
Source: Shiha G et al, Lancet Gastroenterology, 2021 / Fouad Y et al, AMAGE guidelines, 2026
Viral hepatitis and other causes
Viral hepatitis, types A, B, C and less commonly E, is a major cause of raised ALT and AST across the Arab world. In acute viral hepatitis, ALT can rise to hundreds of times the upper limit of normal. In chronic hepatitis B or C, the rise may be mild for years and then escalate as the disease progresses toward cirrhosis.
A sudden acute rise in ALT of ten times the upper limit or more suggests either acute viral hepatitis or acute drug-induced liver injury. This pattern requires the same urgent assessment on the same day, regardless of which cause is suspected. Autoimmune hepatitis, in which the body's immune system attacks its own liver, disproportionately affects women and can produce a pattern similar to viral hepatitis.
Inherited conditions account for a minority of cases but are important to exclude, particularly in younger patients with unexplained raised enzymes. Wilson's disease, in which copper accumulates in the liver, and haemochromatosis, in which excess iron is deposited, both raise ALT and are treatable if caught before cirrhosis develops. Your doctor will ask about family history and may add specific blood tests to rule these out.
Medicines and supplements: the cause that is often forgotten
Drug-induced liver injury is a common and commonly underestimated cause of raised liver enzymes in the Arab world, where paracetamol, antibiotics and painkillers are widely available without prescription and often taken at higher doses than recommended. Paracetamol at excessive doses is the leading cause of acute drug-induced liver failure globally, and the threshold for harm is much lower if someone is already fasting, malnourished or drinking alcohol.
Among prescribed medicines, statins occasionally cause a mild rise in ALT in a small percentage of users, which usually stabilises and does not require stopping the medicine. Anti-tuberculosis drugs, antiepileptics, some antipsychotics and hormonal medications all have the potential to raise liver enzymes, which is why liver tests are often repeated at intervals in patients on these treatments.
Herbal supplements and weight-loss preparations are a particularly important group in the regional context. Extracts sold as slimming teas, certain traditional herb preparations, high-dose aloe vera and some traditional Chinese medicine formulations have been associated with significant drug-induced hepatitis. Patients frequently do not mention supplements to their doctor because they do not consider them medicines. If you are taking any supplement and your enzymes are raised, tell your doctor immediately. In most cases the enzymes return to normal within weeks of stopping the supplement.
What happens after an abnormal enzyme result
The first step is to confirm the result is genuinely persistent. A mild single abnormal reading may be transient. Your doctor may repeat the test after two to four weeks while asking you to avoid known triggers such as intense exercise, new supplements or unusually fatty meals, before proceeding to a full investigation.
If the raised result is confirmed, your doctor will use the pattern of results and your history to narrow the likely cause. Additional tests often include: hepatitis B surface antigen (HBsAg) and hepatitis C antibody (Anti-HCV), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), bilirubin, a full lipid profile, fasting glucose, and thyroid function. Each adds a piece to the picture and often allows a diagnosis without needing a biopsy.
An ultrasound of the abdomen is the standard first imaging step. It takes only a few minutes, uses no radiation and no injected contrast, and is available in most radiology centres across the Arab world at reasonable cost. It will show whether the liver looks fatty, whether there is enlargement of the spleen suggesting portal hypertension, and whether the gallbladder carries stones that might be causing elevated liver enzymes through a different mechanism.
Liver health and the bigger picture
Liver enzymes sit within a broader picture of metabolic health. They are directly linked to diabetes control, blood lipid levels, body weight, physical activity, diet quality and medication burden. Improving these factors produces measurable improvements in enzyme levels in the majority of patients, which is why the first advice after a raised ALT is usually about lifestyle rather than a specialist prescription.
A 2019 global review published in Hepatology by Younossi and colleagues, using data from dozens of countries, showed that MAFLD has become the leading cause of advanced liver disease worldwide, and that the window of opportunity to prevent progression from simple fatty liver to fibrosis and eventually cirrhosis is exactly the stage at which raised enzymes are first discovered.
The liver is an organ of extraordinary regenerative capacity. In the absence of established cirrhosis, its ability to recover once the cause of injury is removed is remarkable. This means that an early raised ALT is not a sentence but an invitation: to find the cause, remove it where possible, and give the liver the conditions it needs to recover. Regular follow-up with your doctor and honest reporting of everything you take is the foundation of good liver care.
You can log your liver enzyme results in the Sihtak app and watch them trend over time as a clear graph to share with your doctor. The AI assistant can help you understand what a specific ALT or AST value means and whether it warrants prompt attention.
Frequently asked questions
What is the difference between ALT and AST?
Both are liver enzymes, but ALT is more specific to the liver. A rise in ALT alone almost always points to a liver problem. AST is also present in heart and skeletal muscle, so a rise in AST without a corresponding rise in ALT can indicate muscle injury, a heart attack or intense exercise rather than liver disease. Your doctor interprets both together with the clinical context.
Does fatty liver always raise ALT?
Not always. Some patients with fatty liver confirmed on ultrasound have completely normal ALT levels, because enzymes only rise when there is active cell damage and inflammation. This is why imaging is sometimes needed even when enzyme levels are normal. Conversely, normal enzymes do not rule out the presence of fat in the liver.
Can medicines cause a raised ALT?
Yes, and more commonly than most patients realise. Paracetamol in excess, statins, tuberculosis medicines, some antibiotics and herbal or slimming supplements can all raise ALT. Tell your doctor about everything you take, including supplements and herbal preparations, whenever you are reviewing enzyme results. This information changes the entire interpretation.
At what level does raised ALT become urgent?
A rise above three times the upper limit of normal warrants prompt medical review, ideally within days. A rise above ten times the upper limit, or any rise accompanied by jaundice, dark urine, severe abdominal pain or confusion, is a same-day emergency that needs hospital assessment.
Does raised ALT mean liver cirrhosis?
No. Raised ALT means liver cells are being damaged and leaking their contents into the bloodstream. This is not cirrhosis. Cirrhosis is a late-stage scarring that develops over years of uncontrolled inflammation. Catching raised enzymes early and finding the cause is precisely how cirrhosis is prevented, not a sign that it has already happened.
Can liver enzymes return to normal?
Yes, very often. In fatty liver disease, enzymes typically normalise with sustained weight loss and improved diet. In drug-induced liver injury, they usually return to normal within weeks of stopping the offending medicine. The liver's regenerative capacity means that early intervention, before cirrhosis develops, has an excellent chance of full recovery.
Do I need to fast before a liver function test?
No. ALT, AST, bilirubin and most other liver function markers are not affected by a single meal and can be tested at any time of day. Fasting may sometimes be requested to combine liver tests with cholesterol or glucose measurement in the same appointment, but the fasting requirement in that case is for the lipid or glucose part, not for the liver enzymes.
Sources
- Fouad Y, Alboraie M, Shiha G et al: Epidemiology and diagnosis of metabolic dysfunction-associated fatty liver disease, Hepatology international, 2024
- Shiha G, Alswat K, Al Khatry M et al: Nomenclature and definition of metabolic-associated fatty liver disease: a consensus from the Middle East and north Africa, The lancet. Gastroenterology and hepatology, 2021
- Fouad Y, Elwakil R, Sanai FM et al: The African Middle East Association of Gastroenterology (AMAGE) clinical practice guidelines for the diagnosis and management of metabolic dysfunction associated fatty liver disease, Annals of hepatology, 2026
- Amernia B, Moosavy SH, Banookh F et al: FIB-4, APRI, and AST/ALT ratio compared to FibroScan for the assessment of hepatic fibrosis in patients with non-alcoholic fatty liver disease in Bandar Abbas, Iran, BMC gastroenterology, 2021
- Xuan Y, Wu D, Zhang Q et al: Elevated ALT/AST ratio as a marker for NAFLD risk and severity: insights from a cross-sectional analysis in the United States, Frontiers in endocrinology, 2024
- Younossi Z, Tacke F, Arrese M et al: Global Perspectives on Nonalcoholic Fatty Liver Disease and Nonalcoholic Steatohepatitis, Hepatology (Baltimore, Md.), 2019
This content is for health education only and is not a substitute for medical advice. If you have symptoms that worry you, see your doctor.