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Potassium Blood Test

Original price £39.00 - Original price £39.00
Original price
£39.00 - £39.00
Current price £39.00

Measure the level of potassium in your bloodstream - an essential electrolyte crucial for nerve and muscle function, including heart rhythm.

  • Biomarkers: 1
  • Turnaround: 1-2 days

Simple and accurate blood test from a laboratory you can speak to.

Step 1. Choose sample collection option

Currently selected option: CLINIC APPOINTMENT

  • Add same or next day appointment during checkout.
  • Rapid results - no waiting for the kit, no finger pricking, no posting the sample back.
  • Blood collection from your arm by our professional nurses.
  • Single appointment covers all your tests on the day.
  • Clinics in London, Brighton/Hove, Croydon, Guildford, Reigate, Royal Tunbridge Wells and Crawley.

Clinic too far? Get a home kit by selecting "HOME KIT" as sample option, it's the same test.

Understanding your potassium levels is crucial for achieving optimal health. This essential mineral plays a key role in regulating blood pressure, fluid balance, and muscle and nerve function. A Potassium Blood Test offers invaluable insights into your overall well-being, helping you and your healthcare provider make informed decisions about your diet, lifestyle, and any necessary treatments. With accurate and quick results, you will be empowered to take proactive steps in managing your health effectively.

Due to the very unstable nature of potassium, it is not possible to offer this kit as a home sample collection. The sample needs to be in our labs within 8 hours of collection, which is not always possible in a home kit.

If you would like a potassium test, please come into one of our clinics.

About the Potassium Blood Test

The Potassium Blood Test is a vital diagnostic tool designed to measure the level of potassium in your blood. This essential mineral is pivotal for a range of bodily functions, including regulating blood pressure, maintaining fluid balance, and ensuring proper muscle and nerve function. Accurate measurement is critical for assessing your overall well-being and guiding healthcare decisions.

However, it is important to note that potassium has a very unstable nature, making it unsuitable for home sample collection kits. To ensure the most accurate results, the sample must reach our labs within 8 hours of collection, a timeline often unachievable with home kits. Therefore, if you are interested in getting a Potassium Blood Test, we strongly recommend visiting one of our clinics for sample collection. This approach guarantees the timeliness and accuracy essential for effective health management.

1 Biomarker


    - Potassium (venous only)


    Need more biomarkers? Check out our Electrolytes Blood Test.

Most of the biomarkers we offer in the "ready made" panels are also available separately. So if your favourite test panel is missing a biomarker you would like to have, no problem, you can add whatever you need to one of our standard panels using the "Pick-n-mix" options, such as this one.


    For most biomarkers our usual turnaround time is 24-48 hours, or less, from the time your sample is in our lab. We do not wait for all the results to complete before sending them to you, so you may start receiving results the same day for most cases, or as results become available.

    We are extremely proud of our very short turnaround times and a very efficient laboratory processes. Whilst we accommodate the shortest of time scales, with some results available within hours, for this particular test the usual turnaround time is:

    1-2 days

Doctor's notes

Hi, I am Dr. Adam Staten and here's my view on this test as a GP and Clinical Director at One Day Tests.

The Potassium Blood Test offered by One Day Tests is a vital tool for assessing key aspects of your health, including blood pressure regulation, fluid balance, and proper muscle and nerve function. An imbalance in potassium levels can lead to significant health concerns, making it crucial to monitor them accurately.

Given potassium's sensitive nature, our advanced lab facilities are specifically designed to handle its instability, thereby ensuring precise results. This test is an integral component of any comprehensive healthcare strategy. 

With accurate readings, your healthcare provider can offer targeted advice and treatment options, guiding you towards optimal health. Trusting this critical diagnostic measure to the professionals at One Day Tests means you are taking a proactive and informed step in managing your well-being.

Red flag symptoms for the Potassium Blood Test

Even if your blood tests are normal, you should see a doctor if you have any of the symptoms below because they may be a sign of serious underlying illness:

  • Fatigue or weakness
  • Breathing difficulties
  • Irregular heart rhythm
  • Severe headaches
  • Palpitations or chest pain
  • Excessive thirst or urination
  • Muscle twitching or cramps

Your Results and Health Dashboard

The results of your Potassium Blood Test will be emailed to you as a secured PDF file, ready for your GP and will also be uploaded to our Health Dashboard area of the website. It’s a unique and powerful tool, powered by our in-house clinical analysis research, to match your biomarkers across test panels and symptoms, as well as provide clinical commentary on all individual biomarkers you tested for.

The health dashboard will also provide "panel level" commentary - a birds eye view of the biomarkers that were tested. This feature allows you to view your test results and clinical commentary, and compare them to previous results, giving you a clear understanding of how your health is progressing.

By using the Health Dashboard, you can identify changes in your biomarkers and make necessary adjustments to your lifestyle. This added value is immense, as it empowers you to monitor your health and make informed decisions about your well-being.

It's free and is available with all of our tests.

Save on continuous monitoring with our subscription plan

The best way to look after your health is to do so regularly. This is easy to do with our continual monitoring plans which give you a discount on future blood tests. You choose the frequency and we'll do the rest.

When you purchase a subscription, we will deliver your home test kits or allow you to book appointments in line with your chosen frequency. You will be able to track your biomarkers over time in our powerful Health Dashboard, where results will be automatically updated for you. There is a minimum of 3 tests with any subscription, after which you can pause/restart/cancel at any time.

Special instructions

Hi, I am Stefania Brown, I am the Laboratory Manager at One Day Tests and here are the lab's special requests for the Potassium Blood Test.

You don't need any special preparations for a potassium blood test, just ensure you are hydrated and avoid caffeine where possible.

Venepuncture appointment - how to prepare

If you are coming into one of our clinics for the test, this is what you need to do before you arrive:

  • Drink plenty of water about an hour before the appointment.
  • Avoid coffee/tea/energy drinks. Water is good!
  • That’s it! We’ll do the rest.

Home test kit for Potassium Blood Test - how it works

Our blood test kits are simple and convenient.

The most important step in doing a blood test at home is to read the instructions very carefully. The process is very simple, but there are a few pitfalls you need to be aware of - you will save yourself a lot of time if you do it right the first time around!

  • Full printed instructions will arrive with your kit - please read them carefully.
  • Drink plenty before taking the sample and warm your hands up in the sink with warm water for a few minutes. This will make your blood flow much better.
  • Fill the tubes to the top line. We don’t need much blood; filling tubes to the top line is about 15 drops of blood.
  • Post the samples on the same day you take them, before midday, Monday to Thursday. If you post it any other time it might get to us late or be stuck at a sorting office over the weekend. You will then have to do it again.
  • Package the sample in the same box the kit came in. Otherwise, Royal Mail or DPD will reject it. The sample tubes go into a pouch, then into a cardboard box, and then into a return envelope. All of this is provided in the kit: please use it.

We look forward to receiving your sample in our lab!

How the finger prick home test kit for Potassium Blood Test works - from Dr. Adam Staten

Why choose us?

Hello! My name is Dr. Vinesh Mistry, I am part of the GP team here at One Day Tests and here is why you should trust us to test your blood.

We run our own regulated laboratories and our own accredited clinics. We manufacture our own approved home sample collection kits. Your results are looked after by our fantastic clinical governance team and our super-talented biomedical science team.

When you book your test with us - you book directly with the lab. This means accuracy and responsible duty of care, direct access to the provider and extremely fast turnaround times.

Finally, our customer services rock! You can ask the lab a question any time or you can speak to a real human. It's good to WhatsApp, email on or give us a call on 0845 527 07 67.

Frequently Asked Questions

Hi, I am Lana Nela, Lead Nurse, and here is what we are frequently asked about this test.

Why do I need to take this test in a clinic?

Due to the unstable nature of potassium, the sample needs to reach our labs within 8 hours of collection. Home sample collection kits cannot guarantee this timeframe, so the test must be taken at a clinic.

What are the normal ranges for potassium?

Normal levels typically range from 3.6 to 5.2 millimoles per litre (mmol/L). However, slight variations might be considered normal depending on the lab and individual health factors.

What conditions could abnormal potassium levels indicate?

High or low levels of potassium could indicate various conditions like kidney disease, heart disorders, or hormonal imbalances.

Why take this test?

Hi, I am Dr. Marco Esposito and here is why it's important to take this test.

  • If you're experiencing symptoms such as irregular heartbeat, muscle weakness, or fatigue, a Potassium Blood Test can provide valuable information on your body's electrolyte balance
  • For individuals managing chronic conditions like hypertension or kidney disease, keeping track of potassium levels is essential
  • Monitoring potassium is particularly vital if you're on medications like diuretics or beta-blockers

Is this test right for you?

Hi, I am Sandeep Patel, I am the Laboratory Director at One Day Tests. Here are the symptoms that you may wish to address with this test.

This test is a vital resource for anyone committed to maintaining their well-being or for those who suspect something might be amiss with their health.

This test offers indispensable insights into your potassium levels, which play a crucial role in muscle contraction, nerve function, and heart health. Should you be experiencing muscle cramps, irregular heartbeats, or unexplained fatigue, this test can provide the answers you need to target your healthcare regimen effectively. It's particularly invaluable for those on medications that affect potassium levels or with conditions that may impact electrolyte balance.


    Make your own test panel

Why blood tests are important.