Long Covid Breathlessness: Everything You Need to Know in 4 Minutes

Reading time: approximately 5 minutes | Updated: October 2026 | Brain fog friendly

Long COVID breathlessness can make breathing feel difficult, uncomfortable or strangely incomplete, even when your oxygen levels, chest X-ray and lung function tests are normal.

Research suggests several possible contributors, including autonomic dysfunction, altered breathing patterns, reduced exercise tolerance and changes in how the body uses oxygen. Microvascular and cellular energy abnormalities are also being investigated.

There is no single explanation for everyone. The important thing is to understand what your breathlessness feels like, when it happens and what might be worth investigating or trying.

Key Takeaways

• Normal oxygen levels do not mean your symptoms are imaginary. A pulse oximeter measures blood oxygen saturation, not every aspect of breathing or exercise tolerance.
• Breathlessness can have different causes. Lung conditions, breathing pattern changes, autonomic dysfunction and other problems can overlap.
• When it happens matters. Breathlessness on standing, during activity or at rest may point towards different possibilities.
• Post-exertional malaise (PEM) changes the advice. Pushing through activity can worsen symptoms in people who experience PEM.
• Some approaches may help, including supported breathing retraining, pacing, positioning and treatment of an identifiable underlying condition.

If You’re Too Breathless or Foggy to Read Everything

Start with the part that sounds most familiar.

What you’re experiencing	Read this section
Normal tests but breathing still feels wrong	Why Are My Tests Normal?
Breathlessness when standing	When Standing Makes Breathing Harder
Feeling you cannot get a satisfying breath	Air Hunger
Worse after activity or the following day	Breathlessness and PEM
Want something practical to try	What Might Actually Help?
Worried about a new or severe symptom	When to Seek Urgent Help

---

You walk from the bedroom to the kitchen.

A journey that used to require absolutely no thought now leaves you wondering why breathing has suddenly become an activity.

Perhaps you stop halfway up the stairs. Perhaps you sit down after a shower. Or perhaps you’re doing nothing at all when you notice that your breathing feels wrong.

Not necessarily fast. Not necessarily noisy.

Just wrong.

You try taking a deeper breath, but it doesn’t feel satisfying. So you take another. And another.

Then you check your oxygen levels.

98%.

Perfectly normal.

Which would be reassuring if you didn’t still feel as though someone had quietly changed the rules of breathing without telling you.

For many people with Long COVID, this is one of the most confusing symptoms: feeling breathless while being told that the tests look fine.

But breathlessness is a sensation produced by several systems working together. The lungs are important, of course, but so are the heart, circulation, nervous system, respiratory muscles and the brain’s interpretation of breathing signals.

And that is where the story becomes more interesting.

Why Does Long COVID Cause Breathlessness?

The short answer: there may be more than one reason, and not all of them involve visible lung damage.

Some people develop respiratory complications following COVID, particularly after severe infection. Others have persistent breathlessness despite reassuring imaging and conventional lung function tests.

Researchers are exploring several possibilities.

Autonomic dysfunction

Your autonomic nervous system helps regulate heart rate, blood pressure and other automatic functions. In some people with Long COVID, these responses become less stable.

Standing up, changing position or performing a small amount of activity may produce a disproportionate increase in heart rate and an uncomfortable sensation of breathlessness.

This can occur alongside POTS or other forms of orthostatic intolerance.

Altered breathing patterns

Some people develop breathing pattern disorders, where the rhythm, depth or mechanics of breathing become less efficient or comfortable.

You may breathe more rapidly, use upper-chest muscles excessively or repeatedly feel the need to take a deep breath.

This is a real physical experience. It should not automatically be dismissed as anxiety.

Equally, not every person with air hunger has a breathing pattern disorder, so assessment matters.

Changes in oxygen use and exercise physiology

Some studies of people with persistent symptoms after COVID have found abnormalities in exercise responses, including how oxygen is extracted or used by tissues.

These findings may help explain why some people feel disproportionately breathless or exhausted during activity despite normal resting oxygen levels.

However, the findings vary between studies and do not establish one universal mechanism.

Microvascular changes and microclots

Researchers have investigated abnormalities involving small blood vessels, clotting proteins and fibrin-containing particles in Long COVID.

These are important research questions, but it has not been established that microclots are the cause of breathlessness in every patient, or that a normal pulse oximeter reading proves oxygen delivery is being blocked by them.

Mitochondrial and metabolic changes

There is also growing interest in how Long COVID affects energy metabolism.

Mitochondria help cells produce usable energy. Research has identified metabolic abnormalities in some people with Long COVID, but their precise contribution to breathlessness remains under investigation.

The useful conclusion is not that everyone has four separate problems.

It is that the same symptom can have different explanations, and understanding the pattern may help you find a more appropriate approach.

Why Are My Tests Normal When I Still Can’t Breathe Properly?

This is often the question that brings people to Long COVID communities in the first place.

You’ve had a chest X-ray. Perhaps a CT scan. Your oxygen levels look normal. Your GP listens to your chest.

Everything seems reassuring.

And yet walking to the bathroom can still feel like climbing a hill.

The explanation is that different tests answer different questions.

A chest X-ray can identify certain structural abnormalities. Spirometry assesses airflow. A pulse oximeter estimates how much oxygen is carried by haemoglobin in your blood.

These are valuable tests, and normal results can help rule out important problems.

But they do not measure every possible cause of breathlessness.

For example, a normal resting oxygen reading does not tell us how your heart rate behaves when you stand, whether your breathing pattern changes during activity, or whether you experience abnormal exercise responses.

That doesn’t mean standard tests are useless or that they always miss Long COVID.

It means persistent symptoms may require a more individualised assessment.

And it is worth remembering that normal results should not automatically be attributed to Long COVID either. Asthma, anaemia, cardiac problems, sleep-related breathing disorders and other treatable conditions may need consideration.

Three Ways Long COVID Breathlessness Can Feel

1. Breathlessness During Activity

You walk upstairs, carry groceries or have a shower, and suddenly breathing becomes noticeably harder.

Sometimes it settles after a short rest. Sometimes the activity also triggers fatigue, dizziness or palpitations.

And sometimes the consequences arrive later.

This is where it becomes important to distinguish breathlessness during exertion from post-exertional malaise.

You can become breathless during activity without experiencing PEM.

PEM is different: symptoms worsen after exertion, often with a delay, and recovery can take much longer than expected.

2. When Standing Makes Breathing Harder

You feel relatively comfortable lying down, but standing up makes your heart race and your breathing feel uncomfortable.

Perhaps you become light-headed, shaky or unusually weak.

This pattern may suggest an orthostatic problem, including POTS or another form of autonomic dysfunction.

It doesn’t prove that you have POTS, but it is useful information to share with your clinician.

If the symptoms improve when you sit or lie down, mention that too.

3. Air Hunger: When You Cannot Get a Satisfying Breath

This is the particularly strange one.

You’re sitting quietly. Your oxygen levels are normal. Yet you cannot seem to take a breath that feels complete.

You sigh. You yawn. You try another deep breath.

Nothing quite satisfies the sensation.

Some people describe it as breathing through a straw. Others say they feel the need to keep reminding themselves to breathe.

Breathing pattern changes may contribute in some cases. Other respiratory, cardiovascular or neurological causes can also produce uncomfortable breathing sensations.

The experience is real, even when a routine test doesn’t immediately explain it.

And if you find yourself repeatedly trying to take enormous breaths, that can sometimes make the sensation worse rather than better.

Breathlessness and PEM: When Yesterday Catches Up With You

Imagine having a slightly better day.

You go to an appointment, manage a conversation, perhaps stop at the supermarket on the way home.

You feel reasonably pleased with yourself.

Then the following day, breathing feels harder. Your muscles ache. Your fatigue deepens. Even sitting upright feels like work.

This may be post-exertional malaise (PEM).

PEM is a worsening of symptoms following physical, cognitive, emotional or other exertion. The deterioration may be delayed by hours or longer and can last days or sometimes weeks.

Not everyone with Long COVID breathlessness experiences PEM.

But if you do, it changes how activity and rehabilitation should be approached.

The familiar advice to gradually increase exercise regardless of symptoms may be inappropriate and can provoke deterioration.

What might be worth trying?

Notice whether breathlessness is worse immediately after an activity, later that evening or the following day.

You don’t need a complicated symptom tracker.

Something as simple as:

Tuesday: hospital appointment. Wednesday: worse breathing, heavy legs and exhaustion.

If you see a repeated pattern, consider whether pacing and reducing activities that trigger crashes might help.

Our guide to living with PEM explores practical ways to manage your energy.

What Might Actually Help?

There is no single treatment for Long COVID breathlessness because there is no single cause.

But there are approaches worth discussing, and some are surprisingly simple.

Breathing Retraining

For people with an identified breathing pattern disorder, specialist breathing retraining may help reduce symptoms.

This is not about taking bigger breaths or forcing yourself to breathe more deeply.

In fact, repeatedly taking large breaths can sometimes increase discomfort, dizziness or the sensation of air hunger.

A respiratory physiotherapist familiar with breathing pattern disorders and Long COVID can assess whether retraining is appropriate.

Worth knowing: Breathing exercises are not a universal treatment for Long COVID breathlessness, and they should not replace investigation of other causes.

Positioning

Sometimes the most useful advice is also the least complicated.

Some people find it easier to breathe when sitting slightly forward with their arms supported on their knees or a table.

Others prefer lying on their side or keeping their upper body slightly elevated.

These positions may help reduce the work of breathing or simply make the sensation more manageable.

Try whichever feels comfortable rather than forcing a particular position.

A Gentler Breathing Rhythm

If your breathing becomes rapid or uncomfortable, you may find it helpful to relax your shoulders and allow your breathing to become quieter and less effortful.

Some people benefit from a gentle, slightly longer out-breath.

The key word is gentle.

Don’t force a deep inhalation, hold your breath or follow a rigid counting exercise if it increases dizziness, distress or air hunger.

And if your breathlessness is new, severe or rapidly worsening, breathing techniques are not a substitute for medical assessment.

Managing Postural Symptoms

If breathlessness occurs mainly when standing, it may be worth asking whether orthostatic intolerance is contributing.

For people with a diagnosed condition such as POTS, management may include hydration, compression garments, medication or other measures depending on individual circumstances.

Increasing salt or fluid intake is not appropriate for everyone, particularly those with certain heart, kidney or blood-pressure conditions.

Our POTS and dysautonomia guide explains why standing can make symptoms worse.

Pacing Rather Than Pushing Through

If breathlessness is part of PEM, reducing repeated crashes may be more useful than trying to build endurance through a fixed exercise programme.

That can mean sitting to shower, dividing tasks into smaller parts, taking breaks before symptoms escalate or using practical aids to reduce unnecessary exertion.

These aren’t signs of giving up.

They’re ways of spending a limited energy budget more carefully.

Pulmonary Rehabilitation: Helpful for Some, Not Everyone

Pulmonary rehabilitation can improve breathlessness and physical function in selected patients with respiratory problems.

Some post-COVID rehabilitation studies have reported benefits.

However, rehabilitation needs to match the individual.

If you experience PEM, tell the rehabilitation team before starting. A programme based on steadily increasing activity despite symptom deterioration may not be suitable.

The question isn’t simply whether rehabilitation works.

It’s which rehabilitation, for which patient, and under what conditions.

Why Breathlessness Can Feel So Frightening

Breathing is one of those things we usually take for granted.

Until it becomes difficult.

Then it can occupy your entire attention.

You notice every breath. You wonder whether the next one will feel normal. You check your oxygen levels again, even though they were fine ten minutes ago.

Breathlessness naturally activates the body’s threat response. Feeling frightened can then change breathing patterns and make the sensation more intense.

But this does not mean anxiety caused the original symptom.

A physical symptom can be frightening. Fear can amplify it. Both things can be true.

And being told to calm down when you feel you cannot breathe is rarely the reassurance anyone thinks it is.

Sometimes the most helpful first step is having the symptom properly investigated and understanding what might be contributing to it.

What to Tell Your GP

Instead of saying only, “I’m breathless,” try describing the pattern.

• When does it happen? At rest, standing, walking or lying down?
• What does it feel like? Air hunger, chest tightness, rapid breathing or difficulty taking a satisfying breath?
• What comes with it? Palpitations, dizziness, chest pain, coughing or fatigue?
• What happens afterwards? Does it settle quickly, or do symptoms worsen later?
• What helps? Sitting, lying down, changing position or resting?

Depending on your symptoms and previous investigations, your GP may consider checking for respiratory, cardiac, haematological or autonomic causes.

A referral to respiratory physiotherapy may be appropriate if a breathing pattern disorder is suspected.

In selected cases, clinicians may consider more specialised exercise physiology testing. However, cardiopulmonary exercise testing can trigger PEM, so its potential benefits and risks should be discussed carefully before proceeding.

You do not need to arrive with a diagnosis.

You need to arrive with a clear description of what is happening.

Could Low Ferritin, Anaemia or Gastritis Be Making Breathlessness Worse?

Not every symptom that appears during Long COVID is necessarily caused by Long COVID itself.

Sometimes another condition is adding to the problem and importantly, it may be treatable.

Low ferritin, which indicates reduced iron stores, is one possibility worth checking. Iron deficiency can contribute to fatigue, reduced exercise tolerance and sometimes breathlessness, even before haemoglobin falls enough to cause anaemia.

If iron-deficiency anaemia develops, breathlessness may become more noticeable because the blood has less haemoglobin available to transport oxygen.

There can also be a connection with the digestive system.

Gastritis, particularly when associated with Helicobacter pylori infection or autoimmune gastritis, may interfere with iron or vitamin B12 absorption. Some gastrointestinal conditions can also cause slow blood loss, gradually reducing iron stores.

This doesn’t mean gastritis is causing your Long COVID breathlessness. It means that several problems can coexist, and identifying a treatable contributor may make a meaningful difference.

What might be worth asking your GP?

Depending on your symptoms and medical history, a full blood count, ferritin and other iron studies may be appropriate. Vitamin B12 testing or investigation of gastrointestinal symptoms may also be relevant.

And remember: a normal haemoglobin result does not necessarily exclude iron deficiency.

The aim isn’t to explain every Long COVID symptom through low iron. It’s to make sure something treatable isn’t being missed.

When to Seek Urgent Help

Long COVID can cause persistent breathlessness, but new or worsening breathing symptoms should not automatically be assumed to be Long COVID.

Call 999 for severe difficulty breathing, sudden breathlessness with severe chest pain, collapse, or other signs of a medical emergency.

Seek prompt medical advice for new or worsening breathlessness, especially with chest discomfort, coughing blood, fainting, new one-sided leg swelling or unexpectedly low oxygen readings.

If you’re unsure how urgently you need help in the UK, NHS 111 can advise. Do not delay emergency care to try breathing exercises or wait for symptoms to settle.

Final Thoughts

There is something deeply unsettling about a body that suddenly makes you think about every breath.

Breathing used to happen in the background while you got on with life.

Now you may find yourself planning how to get upstairs, whether you can manage a shower or how far you can walk before needing to sit down.

And when the tests come back normal, it can leave you feeling as though you’re expected to be reassured by a body that still isn’t behaving normally.

But a normal test is not the same as an explanation.

Long COVID breathlessness can involve different mechanisms, and researchers are still working to understand how they overlap.

The practical task is to work out which possibilities are relevant to you, which other conditions need excluding, and what might help without making your symptoms worse.

Sometimes that means a respiratory assessment.

Sometimes it means recognising PEM.

Sometimes it means finding a physiotherapist who understands that breathing retraining isn’t simply telling someone to take a deep breath.

And sometimes it starts with someone finally saying:

“Your oxygen levels can be normal, and your breathing can still feel wrong. Let’s work out why.”

---

Quick Answers

Research and Further Reading

• NICE: Managing the Long-Term Effects of COVID-19 — Assessment and management of ongoing symptoms after COVID.
• NICE: ME/CFS Diagnosis and Management — Relevant guidance on PEM and the risks of inappropriate exercise programmes.
• National Institutes of Health: Long COVID Research — Ongoing research into the mechanisms and treatment of Long COVID.
• NHS: Shortness of Breath — When breathlessness requires urgent medical attention.

Continue Reading on Long Covid Journey

• POTS and Dysautonomia in Long COVID — Why standing can trigger breathlessness, dizziness and a racing heart.
• Post-Exertional Malaise: Living With PEM — How to recognise delayed crashes and manage energy.
• Long COVID Fatigue — Why fatigue and breathlessness can occur together.
• Long COVID Electrolytes — Hydration and autonomic symptoms, including when extra salt may not be appropriate.
• Why Do Long COVID Symptoms Fluctuate? — Understanding good days, bad days and setbacks.

About This Guide

Long Covid Journey brings together scientific research, lived experience and the practical questions patients often ask after an appointment.

We discuss established treatments, emerging possibilities and things worth exploring, while distinguishing what researchers have found from what remains uncertain.

Our lived experience helps us ask the questions. The evidence determines how we answer them.

Medical disclaimer: This article is for information and education, not individual diagnosis or treatment. Seek advice from a qualified healthcare professional about persistent symptoms, medication and rehabilitation. Sudden or severe breathlessness requires urgent medical attention.

---