High uric acid: what it means, what raises it and when to worry

You had a blood test and uric acid came out flagged. The first thing you searched was “high uric acid symptoms”, and this needs clearing up from the start: high uric acid, by itself, cannot be felt. Many people have it elevated without any health problem,^[3] and that is not gout. Gout is something else: a specific attack in a joint, with sudden pain, redness and swelling.^[4] Here is what it is, which numbers the guidelines use, what raises it, what usually goes with it and what to record so the appointment is useful.

Before going on, what does not allow calm reading. Sudden, intense pain in a red, hot, swollen joint, with fever or chills: the British health service treats this as a possible infection inside the joint and asks for urgent care.^[5] Intense pain in the flank or lower back with blood in the urine: a kidney stone picture, seen immediately.^[7] In those cases close this page and seek medical care.

What uric acid is and why it rises

Uric acid is a normal waste product: it forms when the body breaks down substances called purines, found in cells that renew themselves and in many foods and drinks.^[3] It dissolves in the blood and the kidneys remove it in urine; about 65 % leaves through the kidney and the rest mostly through the gut.^[8] It rises by two routes, sometimes combined: the body makes too much, or the kidney removes too little.^[3]

There is a physical fact that explains why this number matters: from about 6.8 mg/dL, at body temperature and pH, urate no longer stays dissolved and crystals can form.^[9] That is why the American rheumatology guideline uses this value to define hyperuricemia.^[1] What the number does not say is whether crystals will form, where or when: that depends on the person, and in most cases it does not happen.^[4]

The numbers: range, definition and target

Three different numbers get mixed up on the same report. The usual reference range runs from 3.0 to 7.1 mg/dL in women and 4.0 to 8.6 in men, with small variations between laboratories.^[2] The definition of hyperuricemia used in reviews starts at 7.0 mg/dL in men and 6.0 in women.^[8] And the target of below 6 mg/dL is for people with gout who are already on treatment; the 2020 ACR guideline strongly recommends it for them,^[1] not for someone with a high number and nothing else. Notice that the range for men reaches 8.6, above the saturation point: an example of why the lab range is not your personal norm.

High uric acid without symptoms is not gout

Asymptomatic hyperuricemia, a high value with no attacks or deposits, is common: between 2.6 % and 36 % of people have it, depending on the population studied.^[8] And most never get gout: “many people with high levels of serum urate will not develop gout”, in the words of the US health institutes.^[4] Even with values above 9 mg/dL, in the observational data cited by the rheumatology guideline only about 20 % developed gout within five years.^[1]

That is where the position of that guideline comes from, which we quote as what it is, a recommendation for doctors and not advice for you: in asymptomatic hyperuricemia, defined as urate of 6.8 mg/dL or more with no prior gout flares or tophi, the 2020 ACR guideline conditionally recommends against starting urate-lowering medication; it calculates that 24 people would need treatment for three years to prevent a single flare.^[1] What it does recommend to those who already have gout, also conditionally: limiting alcohol, purines and high-fructose corn syrup, and a weight loss programme.^[1] A high number without symptoms is not an emergency nor, usually, a prescription: it is a signal to look around.

What raises it

Drinks: fructose, soft drinks and alcohol

Sugary drinks and high-fructose corn syrup raise uric acid because the liver, when processing fructose, releases urate;^[8] meta-analyses link sugar-sweetened soft drinks with higher urate.^[9] Alcohol of any kind raises it,^[3] and beer has a double effect: it brings purines (guanosine) and ethanol speeds up the breakdown of ATP, which ends up as urate.^[8] The British health service suggests to people with gout some alcohol-free days, no more than 14 units a week and not overdoing sugary drinks.^[5]

Food: red meat, organ meats and seafood

The foods richest in purines are red meat, organ meats (liver, kidney) and certain seafood and fish: shellfish, anchovies, sardines, trout, tuna.^[3] Eating a lot of them also raises uric acid in the urine, which is what matters for stones.^[6]

Medicines

Uric acid is raised by diuretics, low-dose salicylates (daily aspirin), niacin, cyclosporine and tacrolimus.^[2] Diuretics and low-dose aspirin are listed as risk factors for gout.^[4] As a guideline position for people with gout: the ACR conditionally recommends switching hydrochlorothiazide to another antihypertensive when feasible, preferring losartan, and not stopping low-dose aspirin when it is indicated.^[1] Never change or stop a medicine because of a result: write it down and bring it to the appointment.

Kidneys, conditions of the day and other causes

Since most uric acid leaves through the kidney,^[8] any drop in its function lets it build up; chronic kidney disease is a risk factor for gout.^[4] If your report also shows high creatinine or low eGFR, the two numbers go to the appointment together. Dehydration and excessive exercise raise it temporarily, and the list of causes also includes chemotherapy, obesity, hypothyroidism, psoriasis and lead poisoning.^[2] The British service also asks to avoid crash diets when losing weight.^[5] And a detail of the test: four hours without eating or drinking before the test, unless told otherwise.^[2]

Both columns come from MedlinePlus,^[2][3] the US health institutes,^[4][6] the British service^[5] and the 2020 ACR guideline.^[1] The right column is not a prescription: those medicines are given for other reasons and only your doctor decides.

What usually goes with it: blood pressure, glucose, triglycerides and waist

High uric acid rarely comes alone. Reviews link it to metabolic syndrome, hypertension, insulin resistance, obesity and type 2 diabetes.^[8] A meta-analysis of 55,607 people found a dose-response relationship between urate and hypertension, and asymptomatic hyperuricemia has been described as an independent risk factor for type 2 diabetes.^[9] Among the risk factors for gout are high blood pressure, chronic kidney disease and metabolic syndrome: high blood pressure, high blood sugar, abnormal cholesterol and excess waist fat.^[4]

This changes the reading. If you also have unmeasured blood pressure, triglycerides at 150 or more, fasting glucose above your usual or a waist that grew, uric acid is one piece of the same picture, and that picture is measured at home: blood pressure seven days in a row, weight and waist once a week, fasting glucose if you have a glucometer.

A high result, an attack and a stone: three different things

A high result

A single high value, without symptoms, asks for three things: repeating it under good conditions (no alcohol or heavy meal the day before,^[5] no intense exercise or dehydration^[2]), putting it in context with your medicines and the other numbers on the report, and comparing it with the previous one. MedlinePlus puts it this way: high levels “don’t always mean you have a condition that needs treatment”.^[3] If you do not yet know how to read a report without panicking, that guide comes first; the other values on the same panel are in blood chemistry.

An attack in the joint

Gout has its own description: pain that starts suddenly, often at night, in a single joint, very often the big toe in the first episode; the joint looks swollen, red and warm, the pain can wake you, and it usually improves within a week or two.^[4] If something like that has happened to you, even if uric acid comes out normal that day, it is a reason to consult soon. Note date, joint, duration and what happened the day before (alcohol, heavy meal, dehydration, illness, injury): those are the triggers the doctor will ask about.^[5]

A kidney stone

Uric acid also forms stones when urine is too acidic; drinking little fluid and having gout raise the risk.^[6] The symptoms: sharp pain in the back, side, lower abdomen or groin, pink, red or brown urine, pain when urinating, sometimes fever and chills; with any of them, medical care right away.^[7] To find out whether uric acid is behind the stones there is a 24-hour urine test, which your doctor decides on.^[3]

Warning signs: when you do not log, you consult

Three situations do not wait for the next check-up:

• Sudden, intense pain in a red, hot, swollen joint, with fever, chills or general malaise: it may be an infection inside the joint and needs urgent care.^[5]
• Intense pain in the flank or lower back, with blood in the urine, pain when urinating or fever: a kidney stone picture, immediate care.^[7]
• Very high uric acid together with high creatinine or low eGFR, or during chemotherapy: in those cases it is watched closely,^[3] and the appointment is now.

What to record and what to bring to the appointment

The uric acid appointment is decided in a few minutes and almost always with one question: “have you had any attacks?”. What you bring in hand defines how good the answer is.

1. All your uric acid results, with dates, not just the latest. The trend is the data.
2. The conditions of the test: hours without food, alcohol or a heavy meal the day before, intense exercise, how much water you drank.
3. The full list of medicines and supplements, with doses: diuretics, aspirin, niacin and everything else.
4. The other numbers on the report: creatinine and eGFR, glucose, triglycerides, cholesterol.
5. Home blood pressure seven days in a row, current weight and waist, and what you drink in a normal week.
6. Any episode of sudden joint pain or renal colic, with date and what happened before.

With that folder, your doctor can decide whether to repeat the test, whether to add 24-hour urine, creatinine or a metabolic profile, and whether the number deserves more than watching. In most cases without symptoms, the answer of the guidelines is to watch and look around,^[1] and that is done better with data than with fright.