A sudden severe headache with that last bench press rep can have one of several possible causes.

There’s a difference between having a history of a sudden headache as you complete your bench press set, and nothing comes of it, and several days later you bench press again, same headache situation…etc., etc., AND the following scenario:

You’ve been bench pressing for years without a hitch, but one day on the last repetition you’re struck by a thunderclap headache: unbearable, sudden in onset, and it persists even though your workout is finished.

Let’s first look at what could be the cause of a sudden headache out of the blue as you grind out that last repetition in the bench press (or other big compound move), and this pain has never happened to you before.

“Sudden onset of headache with intense exercise needs to be investigated,” says Dr. Brian Loftus, board certified neurologist in Bellaire, Texas, who specializes in migraine headaches and multiple sclerosis.

“The first job of the physician investigating is to rule out an intracranial bleed.

“If the patient is seen at the time of the headache – this can usually be done with CT scan of the brain along with a lumbar puncture.

“If the patient is not seen near the time of the acute headache, then it is harder to rule out a bleed.”

In a case such as this, the intracranial bleed would be caused by a ruptured aneurysm that pre-existed in the brain, unknown to the patient.

It could have been there for years. An aneurysm is a dilated, enlarged or bulging section of a blood vessel.

Brain aneurysm bulge. Shutterstock/Veronika Zakharova

Its inner walls are thinned out and weakened (think of a balloon being blown up bigger and bigger; the rubber becomes thinner and weaker).

When you bench press heavy weights and are straining to push out the last few reps, blood pressure is soaring—getting higher and higher as the set progresses towards the end.

This spike in blood pressure, in the event of an intracranial bleed, would have ruptured or torn the aneurysm.

But understand this: Lifting weights does NOT create an aneurysm.

Again, it was already there, possibly for years.

Dr. Loftus says that “it is relatively uncommon to find a bleed.” The brain aneurysm is rare, and you’re far more likely to die in a car accident on the way to the gym.

Resting high blood pressure and smoking are risk factors for an aneurysm.

Nevertheless, you still should see a neurologist if you experienced a sudden severe headache during or even right after a bench press (or deadlift, squat, etc.) set.

If a ruptured aneurysm is not quickly treated, it will be fatal or result in permanent brain damage.

Now, what if you’ve been experiencing the bad headache during or right after bench pressing for some time, and it just goes away?

This isn’t a ruptured aneurysm. It’s likely a primary exertional headache.

It’s benign. In fact, there’s even a name for this: weightlifter’s headache.

The bench presser’s headache can last five minutes to 48 hours, according to the International Headache Society’s International Classification of Headache Disorders.

It can also be pulsating and is sudden in onset, but these features don’t mean it’s serious.

Avoid bench pressing in a hot room; this may help prevent it.

Dr. Loftus diagnoses patients with primary exertional headache if they do not have migraine disorder.

He recommends the drug indomethacin for the “pure” exertional headache, which helps in most cases.

Don’t confuse the sudden severe headache with the gradual onset one—which may develop as a result of dehydration or mental stress. It can also be from a compressed nerve.

One time I was using a dual cable machine and was holding the handles with the inner part of my wrists (I couldn’t grasp with my fingers because this would aggravate my then-golfer’s elbow in the left arm).

The amount of weight was significant, and once I pulled (to simulate a deadlift while standing on a stool), I instantly felt a headache—nothing severe, but it had a “nervy feel” to it. The tension of the handle burrowing into my left wrist was substantial.

When I released my hand, the pain disappeared and never returned. Nerves can be funny. The nerve in the hand originates in the neck, and that’s close enough to the head to refer pain there.

There is yet another possible cause of the intense headache during or after bench pressing, deadlifting or some other multi-joint exercise: venous pressure.

If you have a sudden intense headache while bench pressing or other exercise, it’s also possible that the timing is a coincidence (if it’s a first-time event), and that the cause is unrelated to the exercise, such as a venous sinus thrombosis and meningitis.

Dr. Loftusdr. loftus has a private practice in Bellaire, TX, and focuses on headaches, multiple sclerosis and hyperhidrosis (excessive sweating). He is also board certified in headache medicine.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.  
Top image: Shutterstock/Rido
Source: ihs-classification.org/en/02_klassifikation/02_teil1/04.03.00_other.html