Disclaimer:

This blog post is brought to you by the Department of “Apparently I Know Nothing.” Any resemblance to real domestic discussions is entirely intentional. Medical information below is accurate (because yes, I do actually know my job), but the tone is—how shall we put it—somewhere between “Dad joke” and “mild existential sigh.”

The Interrogation

It always starts the same way.

My wife: “What are liver enzymes again?”
Me: “Hmm, not sure—probably something to do with the liver…”

Fatal error.
You could hear the silent judgment echo through the house. The look said it all: “And they pay you for this?”

To clarify, I do know what liver enzymes are. I spend most of my working life around them, discussing them, and occasionally panicking about them when the results are triple digits and glowing orange on the screen.
But when you’re halfway through your first cup of coffee on a Sunday morning, your brain doesn’t always feel like explaining hepatocellular biochemistry in layman’s terms.

So yes, I gave the classic bloke response: “Dunno.”
And now I’m “the man who works in Upper GI and doesn’t know about livers.”

Right, let’s set the record straight.

What Are Liver Function Tests (LFTs)?

When patients come into hospital with “something not right” in their tummy—pain, jaundice, nausea, or their urine looking like a pint of Guinness—we often run a Liver Function Test (LFT).

It’s not, despite the name, a test of how well the liver functions (that would be far too sensible). Instead, it’s a set of biochemical markers that tell us whether the liver is inflamed, obstructed, or generally grumpy.

Here’s the usual line-up:

Marker	Full Name	What It Tells Us

ALT (Alanine Aminotransferase)

Mainly in liver cells

If high → liver cell injury or inflammation (e.g. hepatitis, fatty liver, alcohol damage)

AST (Aspartate Aminotransferase)

Also in muscles and heart

High alongside ALT = hepatocellular injury; high alone might be muscle-related

ALP (Alkaline Phosphatase)

Found in bile ducts, bones, placenta

If raised → think bile duct obstruction, gallstones, or bone disease

Bilirubin

Yellow pigment from red blood cell breakdown

If high → impaired bile flow or liver clearance; patient often looks like a banana

Albumin

Protein made by the liver

Low = chronic liver disease or poor nutrition

GGT (Gamma-GT)

Enzyme in liver and bile ducts

Raised in alcohol use or biliary obstruction; basically the snitch enzyme

So when we order “LFTs,” what we’re really doing is holding a biochemical mirror up to the liver to ask:
“Mate, are you okay?”

Why Do We Do LFTs in Biliary Problems?

Now, let’s take the classic scenario: someone arrives at hospital, clutching their right upper abdomen and looking deeply unimpressed with life.

They might have gallstones blocking the bile duct (choledocholithiasis), inflammation of the gallbladder (cholecystitis), or even infection in the biliary tree (cholangitis).

Here’s what the LFTs often show:

• ALP ↑ and GGT ↑ → The bile ducts are irritated or obstructed (stone or inflammation).
• Bilirubin ↑ → The bile can’t drain properly, so it spills into the bloodstream (hello jaundice).
• ALT mildly ↑ → Some secondary inflammation from the back pressure.

It’s a bit like a plumbing problem. When the bile duct is blocked, bile backs up, pressure builds, and the liver enzymes rise in protest.

The Diagnostic Dance

Once the LFTs look suspicious, we move to imaging—usually an ultrasound (the “let’s find the stones” test).
If things look really dodgy, a CT scan or MRCP (Magnetic Retrograde Cholangiopancreatography) (fancy MRI of the bile ducts) might follow.

If a stone is stuck in the common bile duct, a gastroenterologist might perform an ERCP (Endoscopic Retrograde Cholangiopancreatography)—essentially fishing the stone out with a camera and a lot of caffeine.

If it’s just the gallbladder playing up, the treatment is often laparoscopic cholecystectomy (keyhole removal of the gallbladder).

And voilà, LFTs usually normalise once the plumbing is sorted.

Other Reasons for Abnormal LFTs

Because I can hear my wife’s voice now: “But what else causes high liver enzymes?”

Oh, where to start…

• Alcohol-related liver disease (ARLD) – ALT and AST rise (AST often > ALT); GGT loves to join in.
• Non-alcoholic fatty liver disease (NAFLD) – linked to obesity and diabetes; ALT > AST pattern.
• Viral hepatitis – huge ALT rises (sometimes >1000).
• Medications – e.g., statins, antibiotics, paracetamol overdose.
• Autoimmune or metabolic conditions – rarer, but always worth checking.

Basically, if LFTs are raised, it’s a clue—but not the full story. You still need to look at symptoms, history, and sometimes do further tests (ultrasound, viral screen, autoimmune screen, etc.).

Might have to write another entry regarding the above.

So, Why Do I Order LFTs?

Because they’re:

• Fast (results in hours),
• Non-invasive,
• Incredibly useful, and
• A brilliant way to look smart when discussing cases on ward round.

They help identify if there’s obstruction, inflammation, or chronic disease, and guide next steps like imaging or surgical review.

In short, they’re one of the most valuable diagnostic tools for anyone walking in with right-sided abdominal pain, jaundice, or unexplained fatigue.

Domestic Reflections

So yes, my dear wife, liver enzymes do matter.
They’re not just random numbers on a blood form, and yes, I might occasionally appear clueless—but only because explaining hepatic biochemistry over Sunday toast isn’t quite as thrilling as you’d imagine.

Someday she’ll find this blog and realise that I do, in fact, know what I’m talking about.
Until then, I’ll continue to live in quiet domestic shame, muttering “ALT… ALP… Bilirubin…” under my breath like some kind of biochemical rosary.

Moral of the story:

Never underestimate the diagnostic power of liver enzymes — or the suspicious gaze of a nurse wife who’s convinced you peaked at anatomy lectures in 2002.