Introduction

If you’re behind the wheel of a commercial truck, your livelihood depends on more than just your driving skills. It depends on your health. Passing a DOT physical isn’t just a routine requirement, it’s a critical checkpoint that determines whether you can stay on the road. Many drivers are surprised to learn that common conditions like high blood pressure, sleep apnea, or diabetes can impact their certification status, sometimes without warning.

The good news? Being informed and prepared can make all the difference. This guide breaks down the most common medical conditions that can affect your DOT exam, what examiners are looking for, and how you can stay compliant so you can keep driving—and keep earning—without unnecessary setbacks.

Hypertension (High Blood Pressure)

Your blood pressure is a vital part of your DOT physical exam and an important indicator of your overall health. Both high and low blood pressure can cause serious complications and increase the risk of accidents.

FMCSA Blood Pressure Guidelines

Controlled Hypertension

If you have been diagnosed with hypertension but your blood pressure is well-controlled with medication, you may qualify for a one-year certification

Blood Pressure Greater Than 140/90 mmHg

Blood pressure readings of greater than 140/90 can lead to temporary disqualification. Drivers in this range are often given a short certification period to bring their blood pressure back under control. If the issue isn’t resolved within the required timeframe, you may be disqualified from driving until your blood pressure meets FMCSA standards.

To learn more about certification length based on blood pressure readings, see the FMCSA Blood Pressure Guidelines for DOT Medical Certification.

Also, find tips for getting a lower blood pressure reading.

Sleep Apnea

While sleep apnea does not automatically disqualify you from driving, it does affect the DOT medical certification process. The FMCSA Medical Review Board provides guidance to medical examiners on when a sleep apnea study should be ordered and how to determine whether a driver is being compliant with their therapy, when needed.

The 2024 FMCSA Medical Examiner Handbook provides a list of risk factors for a person to have sleep apnea. When a driver is found to have three or more risk factors, it is recommended that the medical examiner request that the driver obtain a sleep study. To allow the driver to continue driving while obtaining a sleep study and possible therapy, medical examiners will usually administer a temporary 3-month certificate.

A driver with a diagnosis of sleep apnea will always be limited to a 1-year certification interval, but first, they must demonstrate compliance with their therapy. To be compliant, the driver must be using their sleep-assistive device for a minimum of 70% of nights and for at least 4 hours each night.

Drivers who are unable to demonstrate compliance with therapy may only be granted a 30-day certificate or even disqualified.

Learn more by visiting “Sleep Apnea and DOT Compliance: A Guide for Commercial Drivers”.

Diabetes

Diabetes is a complex disease that can make it challenging for you to control your blood sugar levels. Over time, elevated blood sugar levels can cause damage to many organ systems throughout the body. Drivers with diabetes are more likely to develop other health problems as well.

Part of the exam includes urinalysis which measures the amount of protein, blood, and sugar in your urine. Examiners will use the urine sugar level in conjunction with one or more other lab values to determine level of control. The most helpful is the HbA1c, most referred to as A1c. It is an accurate indicator of your blood sugar levels over the previous three months.

Non-Insulin Dependent Diabetes

The length of certification for a non-insulin dependent diabetic driver is dependent on how well their blood sugars are controlled. Most diabetic drivers are limited to a 1-year certificate. However, a driver with well-controlled diabetes (A1c less than 7%) by be certified for up to 2 years. When blood sugars are poorly controlled, the examiner may elect to limit the driver with a temporary 3-month certificate.

Insulin Dependent Diabetes

The process is slightly different for drivers with insulin-dependent diabetes. Prior to their DOT exam, they will need the Insulin-Treated Diabetes Mellitus Assessment Form (MCSA-5870) completed by their treating clinician. The completed form is only valid for 45 days. The form requests that the driver provide their treating clinician with the last three months of the driver’s electronic glucose logs. You will turn in this completed form to the DOT medical examiner at the time of the exam. The maximum allotted time for an insulin-dependent diabetic driver to be certified is for 1 year.

Mental Health Conditions

If you have a history of mental illness such as depression, regardless of whether you take any medications, you should bring written documentation from your treating provider stating that your current treatment is adequate and effective. The documentation should also state that you are safe and stable to perform the duties of a commercial driver. This will help to avoid delays in receiving your DOT medical card.

For most mental health conditions, the consensus among medical examiners is to limit a driver’s certification interval to 1 year. However, drivers with a diagnosis of dementia, personality disorder, or active psychosis/schizophrenia cannot obtain a DOT medical card.

Get more information about the rules regarding mental illness and commercial driving.

Learn how commercial drivers can navigate through depression.

Hearing or Vision Loss

Failure to pass the vision or hearing component is an automatic disqualifying event. You will need to demonstrate a minimum of 20/40 vision in each eye separately and together. You can do this with or without the aid of corrective lenses. You will also need to have good peripheral vision.

If you only meet this standard in one eye, you may still qualify under the Alternative Vision Standard. To do so, you will need a vision specialist to fill out the Vision Evaluation Report (MCSA-5871). Unfortunately, you will be limited to a 1-year certification interval.

For your hearing, the examiner will give you a forced whisper test. You must hear a forced whisper with at least one ear from five feet away. If you can do so, with or without hearing aids, your examiner will clear you. If you do not pass the whisper test, you will be disqualified until you can obtain an audiometry test. Passing the audiometric test allows you to be certified for up to two years. If you are unable to pass both the whisper test and the audiometry test, there is still the option to apply for a federal hearing exemption.

If you need glasses, contacts, or hearing aids to fulfill these requirements, you must always wear them while driving.

Inner Ear Diseases

These disorders can cause vertigo, a feeling of spinning and dizziness or balance issues. Fatigue, working long hours, smoking, and too much salt in your diet can trigger these symptoms. A classic example is Meniere’s disease. Your inner ear is highly sensitive, and everyday aspects of driving can set off these diseases. These conditions jeopardize your ability to drive correctly and safely.

However, if you can demonstrate being symptom-free for a specified period, you may be able to be medically certified.

Heart Conditions

An active heart condition can be disqualifying until it is resolved or your cardiologist clears you. For the majority of heart conditions, the medical examiner will likely want to establish your specific diagnosis, verify that treatment is effective, and that you are safe and stable to operate a commercial motor vehicle. The medical examiner may send you to a specialist if they still need more information before making a decision. Additional tests may be needed to determine if you’re a danger to yourself and others on the road.

Learn more about murmurs and how they may affect your DOT physical certification in Heart Murmurs: The Affect They Have on the DOT Medical Exam.

Learn more about certification for drivers with heart disease and some heart-healthy tips.

Marijuana Use or Other State-Altering Substances

Marijuana, including CBD, hemp, or cannabis-derived products, can disqualify you even if the product is recommended or prescribed by a licensed medical practitioner. The Drug Enforcement Agency (DEA) banned all schedule I substances such as ecstasy or MDMA, heroin, LSD, mescaline, mushrooms, Quaaludes, MDPV, and marijuana.

Medical Marijuana and the Law

A study of 7 trauma hospitals conducted by the National Highway Traffic Safety Commission revealed 25% of car accident fatalities involved a driver that tested positive for cannabis.

Many states have legalized marijuana for medical use. Some have also legalized it for recreational purposes. However, state acceptance doesn’t equate to federal legalization. Due to marijuana’s ability to alter your mental state, the Department of Transportation (DOT) has a no-tolerance policy. State law may exempt a medical marijuana card carrier from discrimination in the workplace, but all commercial driving companies answer to the DOT. Failed drug tests can cost you your CDL.

Permanent Impairment of an Extremity & the SPE Program

One regulatory requirement that may not get as much discussion is the Skill Performance Evaluation (SPE) certificate under 49 CFR 391.49. The SPE program allows drivers with a certain permanent physical impairment of an extremity to demonstrate that they can safely operate a commercial motor vehicle in interstate commerce.

Who needs an SPE Certificate?

• Drivers, or those planning to become a driver with a commercial driver’s license (CDL) with a fixed deficit (not caused by a progressive disease) of an extremity are eligible. This includes those who are missing, or have permanent loss of function of a hand, foot, leg, or arm.

• The FMCSA specifically lists missing limbs (a hand, finger, arm, foot or leg) as triggers for the SPE requirement if the medical examiner determines it may affect safe operation

View the entire SPE process guide for drivers.

Seizures/Epilepsy

Like inner ear diseases, they are unpredictable and can be triggered by driving. You can lose consciousness and control of the vehicle you are operating at any time. There are a lot of variables that a medical examiner must consider when making a qualification determination for a driver with a history of a seizure or epilepsy.

For example, if a seizure occurred as a result of a known trigger such as a drug reaction, withdrawal, high temperature, acute infectious disease, dehydration, or an acute metabolic disturbance, once the individual has fully recovered, is cleared by a neurologist, and does not require anti-seizure medication, they may be certified for up to 2 years. However, when a seizure occurs without any clear provoking trigger or identifiable cause, the driver must be seizure-free for at least four years before they can obtain a medical certificate.

When a driver has had multiple seizures, they are considered to have epilepsy. When this is the case, the driver must demonstrate that they have been seizure-free for a minimum of eight years before they can obtain a medical certificate.

Conclusion

Maintaining medical fitness is essential for commercial drivers to ensure both personal safety and the safety of others on the road. While many conditions do not automatically disqualify a driver, they often require careful monitoring, proper documentation, and compliance with treatment plans to meet FMCSA standards. Understanding how different health conditions impact DOT certification. Proactively managing them can help drivers avoid delays, maintain their certification, and continue working safely. Open communication with a certified medical examiner and adherence to federal guidelines are key to successfully navigating the DOT physical process.

Medical Review & Authorship

Written by: Dr. Jeffrey Carlson – Chief Medical Officer
Dr. Carlson leads TeamCME’s medical training programs and publishes regularly on DOT medical compliance and examiner best practices.

Reviewed by: Dr. Michael Megehee, DC, NRCME – Founder & Senior Advisor
FMCSA subject matter expert selected to help design the original NRCME educational curriculum and first exam questions.