You can’t catch your breath. The inhale stalls halfway, as if something inside your chest has tightened or locked. You try again and again, convinced the next breath will finally feel complete.

It doesn’t.

You go to urgent care. They listen to your lungs—clear. They check your oxygen—normal. The chest X-ray shows nothing. You’re told everything looks fine.

But it doesn’t feel fine.

If you’ve experienced shortness of breath with normal oxygen levels, you’re not imagining it. And you’re not alone.

When  Tests Are Normal but Breathing Isn’t

This is one of the most frustrating experiences patients describe: a terrifying sensation of air hunger while every test comes back reassuring.

Pulse oximetry measures oxygen saturation in the blood—but not how well oxygen reaches your tissues. Imaging evaluates lung structure—but not how your nervous system regulates breathing. Standard labs assess organ function—but not microvascular oxygen delivery.

When these tests are normal, patients are often told there’s nothing wrong. Some are told it’s anxiety or stress—a label that dismisses the symptom rather than explaining it.

But shortness of breath with normal oxygen levels has real physiologic causes. One that’s frequently overlooked: tick-borne infection.

What Patients Describe

Patients with this symptom are often very specific:

• The inhale feels blocked or incomplete
• Exhaling feels normal
• The sensation comes in waves
• It worsens at night, with heat, or after mild exertion
• Relaxation techniques don’t help

Many describe it as breathing becoming “manual”—as if the automatic drive to inhale has slipped out of sync.

This pattern doesn’t match asthma, COPD, or panic disorder. It matches something else entirely.

The Lyme and Babesia Connection

Lyme disease can disrupt the autonomic nervous system—the system that controls breathing rhythm, heart rate, and other unconscious functions. When this system becomes unstable, breathing may feel shallow, unsatisfying, or effortful even when lung function is normal.

But when Babesia is also present, breathing symptoms often intensify dramatically.

Babesia is a tick-borne parasite that infects red blood cells. It can impair oxygen delivery at the tissue level—even when blood oxygen saturation appears normal. The body senses a mismatch between oxygen availability and demand, and responds by increasing respiratory drive.

The result: an urgent, sometimes overwhelming sensation of not getting enough air.

At the same time, inflammatory signaling may interfere with brainstem centers that regulate automatic breathing. This combination helps explain why patients feel like they’re suffocating while their oxygen readings look fine.

Why This Gets Missed

Most clinicians aren’t trained to connect shortness of breath with normal oxygen levels to tick-borne illness. When standard tests are normal, the workup often stops.

Babesia testing itself has limitations. Standard antibody tests can miss active infection, and not all labs offer the smear or PCR testing that may be more sensitive.

Patients may see pulmonologists, cardiologists, and allergists—all of whom find nothing—before the possibility of tick-borne infection is considered.

This diagnostic gap leaves many patients without answers for months or years.

What Recovery Can Look Like

When Babesia is identified and treated, many patients notice gradual improvement:

• Episodes become less intense
• Nighttime gasping decreases
• The inhale begins to feel fuller
• Breathing slowly becomes automatic again

There’s often a moment—sometimes subtle, sometimes profound—when patients realize the air hunger is no longer dominating their awareness.

For patients navigating these symptoms, understanding the full range of Lyme disease treatment options can help guide conversations with your care team. Recovery is possible, though it often requires patience and individualized care.

What to Ask Your Clinician

If you’re experiencing shortness of breath with normal oxygen levels, consider asking your clinician whether this could be related to autonomic nervous system dysfunction, whether you’ve been fully tested for Babesia and other tick-borne co-infections, and whether there are additional tests beyond standard antibody panels.

Tracking your symptoms—when they occur, what makes them worse, and what other symptoms accompany them—can provide valuable information for your clinician. Patients often notice patterns: worsening at night, with heat, after exertion, or during illness.

Frequently Asked Questions

Why do I have shortness of breath if my oxygen levels are normal? Pulse oximetry measures oxygen in the blood, not tissue-level delivery. Conditions like Babesia can impair oxygen utilization even when saturation appears normal.

Can Lyme disease cause shortness of breath? Yes. Lyme can disrupt autonomic regulation of breathing, causing air hunger, shallow breathing, or the sensation that breathing requires conscious effort.

What is Babesia and how does it affect breathing? Babesia is a tick-borne parasite that infects red blood cells. It can impair microcirculation and oxygen delivery, triggering intense air hunger even with normal oxygen readings.

Is shortness of breath with normal oxygen levels anxiety? Not necessarily. While anxiety can affect breathing, many patients with this symptom have underlying physiologic causes—including tick-borne infection—that standard tests don’t detect.

Can this symptom improve with treatment? Yes. Many patients experience gradual improvement as Babesia and related inflammatory and autonomic stressors are addressed.

Have you experienced shortness of breath that tests couldn’t explain? Share your experience in the comments—your story may help another patient find answers sooner.

References

1. Circulation (2013): Raj SR. Postural tachycardia syndrome (POTS).
2. Nat Rev Neurol (2014): Perry VH, Holmes C. Microglial priming in neurodegenerative disease.
3. Clin Infect Dis (2011): Vannier E, Krause PJ. Human babesiosis.