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Sodium Blood Test

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

This measures the concentration of sodium in the bloodstream, an essential electrolyte crucial for maintaining fluid balance, nerve function, and muscle contraction.

  • 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: HOME KIT via Royal Mail Tracked 24

  • Available everywhere in mainland UK.
  • Includes everything you need to take a safe and suitable blood sample in about 15 minutes.
  • Post the sample back to our laboratory via Royal Mail Tracked 24.

Re-test guarantee

About the Sodium Blood Test

The sodium blood test is a diagnostic tool used to measure the concentration of sodium ions in the bloodstream. Sodium, an essential electrolyte, plays a vital role in maintaining proper fluid balance within the body, transmitting nerve signals, and supporting muscle contractions. This test is particularly useful in assessing electrolyte imbalances, which can have wide-ranging effects on various bodily functions.

The presence of abnormal sodium levels in the blood can indicate underlying health issues. Low sodium levels (hyponatremia) can lead to symptoms like nausea, confusion, and muscle cramps, and may result from conditions such as kidney disorders or hormonal imbalances.

Conversely, high sodium levels (hypernatremia) can cause symptoms like thirst, dry mouth, and confusion, and might be linked to conditions like dehydration or certain medications. 

1 Biomarker


    - Sodium


    Need more biomarkers? Check out our Electrolytes Blood Test.


    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.

Sodium is a crucial electrolyte involved in maintaining fluid balance and regulating the body's pH level. Measuring sodium levels helps evaluate the electrolyte balance in the body, which is essential for proper cellular function, nerve signaling, and muscle contraction.

Abnormal sodium levels can indicate underlying health conditions. The sodium blood test helps diagnose and monitor conditions such as dehydration, kidney diseases, hormonal imbalances (e.g., adrenal gland disorders), heart failure, liver disease, and certain medications that may affect sodium levels.

Red flag symptoms for the Sodium Blood Test

Even if your blood tests are normal, you should see a doctor if you have any of the symptoms below.

  • Extreme thirst and dry mouth
  • Decreased or dark-colored urine output
  • Fatigue and weakness
  • Confusion and disorientation

Your Results and Health Dashboard

The results of your Sodium 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 Sodium Blood Test.

Sodium levels can be affected by dehydration or excessive fluid intake. Therefore, it is important to maintain your regular fluid intake leading up to the test.

Sodium levels can naturally fluctuate throughout the day. If you are continuously monitoring your Sodium levels it is better to keep the sampling time to the same part of the day for more consistent results and easier comparison.

Before this blood test, it is generally recommended to rest and avoid vigorous exercise or activities that may affect your sodium levels temporarily. Engaging in strenuous exercise immediately before the test may lead to temporary alterations in sodium levels.

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 Sodium 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 Sodium 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.

What is the significance of measuring sodium levels in the body?

Sodium is an essential electrolyte that plays a vital role in maintaining fluid balance, nerve function, and muscle contraction. Measuring sodium levels in the blood helps assess the body's electrolyte balance. Abnormal sodium levels can indicate underlying health conditions, such as dehydration, kidney problems, hormonal imbalances, or certain medications.

What factors can influence sodium levels in the body?

Several factors can influence sodium levels in the body, including:

  • Hydration status: Dehydration or excessive fluid intake can impact sodium concentrations.
  • Medications: Certain medications, such as diuretics, may affect sodium levels.
  • Kidney function: Impaired kidney function can disrupt sodium regulation.
  • Hormonal imbalances: Disorders affecting hormones like aldosterone or antidiuretic hormone (ADH) can impact sodium balance.
  • Medical conditions: Conditions like heart failure, liver disease, adrenal gland disorders, and others can influence sodium levels.

Why take this test?

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

It is important in identifying Hyponatremia and Hypernatremia: Hyponatremia refers to low sodium levels, while hypernatremia indicates high sodium levels in the blood. Both conditions can lead to significant health problems.

Hyponatremia can cause symptoms such as confusion, seizures, nausea, and fatigue, while hypernatremia can result in extreme thirst, dehydration, and neurological complications.

This blood test helps detect these imbalances, enabling timely intervention and management.

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.

Symptoms that may indicate the need for a sodium blood test vary depending on whether sodium levels are too high (hypernatremia) or too low (hyponatremia). Here are some common symptoms associated with imbalances in sodium levels:

  • Hyponatremia (low sodium levels): Nausea and vomiting, Headache, Fatigue and weakness, Confusion and disorientation, Irritability and restlessness, Seizures, Muscle cramps or spasms, Loss of appetite, Swelling (edema), especially in the hands and feet
  • Hypernatremia (high sodium levels): Extreme thirst and dry mouth, Decreased or dark-colored urine output, Fatigue and weakness, Confusion and agitation, Seizures, Muscle twitching or spasms, Elevated body temperature, Rapid heartbeat, Swelling (edema)

    Chronic fatigue, Confusion, Fatigue, Irritability, Joint swelling, Muscle cramps, Nausea, Swollen feet, Swollen hands, Thirsty all the time, Vomiting, and Weakness

Why blood tests are important.