What Is The Difference Between a Blood Test and a Breath Test For DUI?

If you’ve been charged with a DUI you need to know the difference between blood alcohol tests and breath alcohol tests so you are able to create an effective defense strategy.

For help with your DUI charges and legal choices, call The Love DuCote Law Firm LLC at 832-471-6904.

Explanation Of Blood Tests And Breath Tests

There are two primary methods for finding out the concentration of drugs or alcohol in your body-breathalyzer tests and blood tests. A breathalyzer test works by detecting the level of alcohol in your breath and then using that information to establish the level of alcohol in your bloodstream. This is a quick and non-invasive test.

By contrast, a blood test involves submitting a blood sample, which is then tested to determine the actual quantity of alcohol or drugs in your bloodstream. Blood tests generally produce more accurate measurements.

Breath Tests For DUI

Since breathalyzer tests for DUI involve using portable breathalyzer machines this type of test is a convenient method of establishing DUI, with the added benefit of the results being available straight away.

Police officers often use breathalyzers at traffic stops to detect if you may be drunk or under the influence of alcohol. You will blow into the handheld device, and the breathalyzer will analyze your breath sample. If the results are above the legal limit for driving, you will most likely be charged with DUI.

Breath test accuracy may be challenged however because other factors may play a part in returning a positive reading. Mouthwash, chewing gum, or certain medical conditions may affect your blood alcohol concentration readings.

Breath test results are not without error and can result in false positives and false negatives. If you’ve been charged with a DUI based on the results of a breath test, you should consult with a DUI defense attorney straight away to review the validity of your results and the circumstances surrounding your testing procedure.

The Love DuCote Law Firm LLC has an outstanding record of reaching the best possible outcome for hundreds of clients accused of a wide variety of criminal charges, including DUI.

Blood Tests For DUI

Blood tests for DUI involve collecting and analyzing blood samples,to test your blood alcohol concentration (BAC) or drug concentration.

Typically the blood will be taken from your arm. Unlike breath tests, blood tests are more accurate and detect a broader range of substances, including controlled or illegal substances.

Blood tests are often used to confirm breath test results or when you’re suspected of being under the influence of drugs rather than alcohol. For the most part they provide more reliable and accurate results, making them a popular option when a more accurate determination is necessary.

A blood test must legally be carried out on you by a trained medical professional, with the collected sample then sent to a laboratory for testing. The results of a blood test may take several days to return from the lab, and generally speaking may delay DUI charges or penalties.

Importantly, blood tests are not without their limitations, and inaccuracies can occur due to improper collection, transportation, storage, or analysis of your blood sample. There’s a chance that these factors may lead to inaccurate results and lead to the results potentially becoming Inadmissible in court.

If you have been charged with DUI based on the results of a blood test, it is essential to consult with an experienced attorney to review and challenge the validity of your results and the testing process conducted on you.

At The Love DuCote Law Firm LLC, we have a proven track record of success in defending hundreds of clients who’ve been charged with DUI to reach the best possible outcome.

What Should You Do If You Have Failed A Breathalyzer Test

You should take immediate steps to protect your legal rights, including:

  • Contact The Love DuCote Law Firm LLC as soon as possible after your arrest. We can advise you of your rights, help you understand the charges against you, and represent you in court.
  • In some states, you have the right to request an independent blood test or another breath test to confirm or refute the initial result. This can be an essential step toward challenging the charges against you.
  • In many states, failing a breath test can result in immediate license suspension, fines, and jail time upon conviction. It’s wise to understand the potential penalties as this can help you prepare for your legal proceedings.
  • Remain calm and composed during your interactions with police officers. Avoid making any statements that could be used against you in court.

What Should You Do If You’ve Failed A Blood Test?

  • Speak with The Love DuCote Law Firm LLC as soon as possible after receiving notice of the failed blood test. We can explain the charges, the consequences, and your defense options.
  • It may be worth challenging your test’s validity in court. If your attorney finds that your blood test results may have been compromised, they may be able to get them thrown out as evidence.
  • Failing a blood test does not necessarily mean that you consumed drugs or alcohol, it just indicates the presence of it in your blood. It could be beneficial to take a follow-up test with an independent medical care provider to confirm or negate your blood test findings.
  • Only discuss your case with your lawyer.


The main difference between a breath test and a blood test for DUI is the method used to establish the amount of alcohol or drugs in your body. A breath test uses your breath while a blood test uses a sample of your blood.

A blood test is more accurate for determining DUI because it directly measures the amount of alcohol or drugs in your body. However, breath tests are often used because they are more convenient and can be used at the scene of where you’ve been stopped.

Yes, breath tests can be inaccurate if they are not properly calibrated or administered. Other factors, such as the presence of mouthwash or food, can also interfere with the results of a breath test.

Yes, blood tests can be inaccurate if they are not properly stored or handled. Contamination during the testing process can also affect the accuracy of blood test results.

Call The Love DuCote Law Firm LLC Today!

Both breath test and blood tests may be used to determine if you are under the influence of drugs or alcohol, each utilizing different methods.

Blood tests are generally considered to be more accurate, however, breath tests are usually more convenient and can be conducted at the scene of a DUI stop.

Importantly, both methods can be inaccurate if not conducted or handled properly. If you’re facing a DUI charge, it’s crucial to contact an experienced DUI defense attorney for advice and representation. At The Love DuCote Law Firm LLC, we’ll provide you with the legal support you need.

Call The Love DuCote Law Firm LLC now, at 832-471-6904 for a free consultation, and give yourself the chance of the best outcome for your DUI case!