Post-Exertional Malaise (PEM)
A worsening of symptoms after physical or mental activity. PEM may be delayed by 12–72 hours and can last for days. It often includes fatigue, pain, brain fog, and flu-like symptoms.
Long COVID is a complex, multi-system condition that can affect anyone, regardless of how mild or severe your original COVID-19 infection was. It describes the persistence of symptoms weeks, months and even years after the acute illness has passed. For some, these symptoms may fluctuate, disappear and return, for some, they can gradually worsen over time.
Please see the links below to formal definitions by:
There is no single “typical” presentation of Long COVID, and that is what makes our work challenging.
Long COVID can impact the lungs, heart, nervous system, immune response, mental health, digestion, hormones, and more, much more.
Many patients experience a combination of symptoms that affect multiple systems at once.
What’s important to know is: you are not alone, and your symptoms are real, recognised, and increasingly understood by clinicians and researchers.
Long COVID is an umbrella term that describes a collection of underlying pathologies.
Over 200 symptoms have been described in Long COVID affecting every body system.
Common symptoms and diagnoses include;
A worsening of symptoms after physical or mental activity. PEM may be delayed by 12–72 hours and can last for days. It often includes fatigue, pain, brain fog, and flu-like symptoms.
A disruption in the autonomic nervous system, affecting functions such as heart rate, blood pressure, digestion, and temperature regulation. Can cause light-headedness, palpitations, and gastrointestinal issues, and is commonly seen in conditions like POTS and MCAS in Long COVID.
Pain, pressure, or discomfort in the chest area, sometimes accompanied by shortness of breath. May occur during rest or activity, and may be related to breathing pattern disorders, inflammation, or autonomic dysfunction.
An abnormal awareness of the heartbeat, which may feel fast, pounding, irregular or fluttering. Often associated with conditions like POTS and may come with dizziness or anxiety.
A profound, ongoing tiredness not relieved by sleep. Often described as exhaustion, it limits day-to-day activities and can worsen significantly after exertion, known as post-exertional malaise (PEM). It can be physical, mental, or both.
Recurring or chronic headaches, including tension-type or migraine-like pain. They can be triggered by exertion, stress, or hormonal changes and may present with light sensitivity or nausea.
A disorder causing inappropriate release of histamine and other chemicals from mast cells, leading to symptoms such as hives, abdominal pain, brain fog, fatigue, and sensitivity to foods, temperature, or smells.
A condition where heart rate increases significantly upon standing, often leading to dizziness, palpitations, fatigue, or fainting. Commonly associated with Long COVID and a key marker of autonomic dysfunction.
Disruptions in hormone levels that may cause irregular periods, hot flushes, mood changes, or fatigue. Long COVID can impact thyroid, adrenal, or reproductive hormones.
Includes bloating, nausea, diarrhoea, and abdominal pain. May be associated with mast cell activation, microbiome imbalance, or food sensitivities developed post-COVID.
Changes in the menstrual cycle, such as missed periods, heavier or lighter flow, or more severe symptoms. These can be caused by hormonal disruptions following COVID-19.
New or worsened sensitivity to specific foods, potentially related to changes in digestion, mast cell activation, or microbiome imbalance.
Sudden or intense emotional responses such as crying, rage, or detachment. Can stem from neurological inflammation, trauma, or hormonal shifts.
A dysfunction of the autonomic nervous system affecting heart rate, blood pressure, temperature regulation, digestion, and more. It may cause symptoms such as fainting, fatigue, GI issues, and orthostatic intolerance.
A condition where the heart beats faster than normal while at rest. May occur in episodes or persistently, and is often associated with anxiety, POTS, or post-viral effects.
Also known as neuropathic pain, this includes burning, shooting, or stabbing sensations. It can affect various parts of the body and may persist long after infection.
Thinning or shedding of hair, often seen several weeks after infection. It may result from stress, nutritional deficits, or autoimmune responses triggered by the virus.
Unusual skin changes such as rashes, hives, or itchiness. These can be inflammatory or linked to allergic-type responses like mast cell activation syndrome (MCAS).
Difficulty maintaining or adjusting to temperature changes. Patients may feel too hot or too cold without environmental cause. May relate to autonomic dysfunction or inflammation.
Symptoms include urgency, frequency, incontinence, constipation, or diarrhoea. May be due to nervous system involvement or immune dysregulation.
A lingering sore or irritated throat that may fluctuate or persist long after the acute phase. Sometimes associated with voice changes or laryngitis.
A dry or productive cough that remains weeks or months after initial infection. May be linked to airway irritation or post-viral inflammation.
A reduced tolerance or exaggerated response to medications that were previously tolerated. May be caused by changes in metabolism, immunity, or nervous system sensitivity.
A reduced capacity to tolerate even mild physical exertion. Can result in breathlessness, fatigue, and post-exertional malaise. A key challenge in Long COVID recovery.
Pain or discomfort in muscles, either generalised or localised. Can worsen with activity and may contribute to fatigue and mobility limitations.
Aching, stiffness, or swelling in joints such as knees, hands, or hips. This pain can fluctuate and may be linked to inflammation or immune response.
Tingling or prickling sensations in the limbs or extremities. Can be episodic or constant and may be linked to nerve irritation or circulation issues.
A persistent ringing, buzzing, or hissing in the ears. May be linked to nerve dysfunction, sensory overload, or vascular issues associated with Long COVID.
Includes blurred vision, floaters, light sensitivity, or double vision. Can be intermittent and associated with fatigue, migraine, or neurological involvement.
An abnormal sensitivity to cold temperatures, potentially linked to poor circulation or autonomic dysfunction. Patients may feel chilled despite warm surroundings.
A heightened sensitivity to light, noise, or touch. Patients may find everyday environments overwhelming or painful. Often linked to nervous system dysregulation and autonomic dysfunction.
Partial or complete loss of the senses of smell or taste. May persist for months and impact appetite, nutrition, and quality of life. Often improves gradually but can be distressing.
Persistent low mood, lack of motivation, or emotional numbness. May stem from the chronic nature of symptoms, isolation, and changes in identity or life roles due to illness.
A heightened sense of worry, panic, or unease, often tied to health uncertainty, trauma, or autonomic dysregulation. Can be both a symptom and a consequence of Long COVID.
Difficulty falling asleep, frequent waking, or non-restorative sleep. Long COVID can disrupt circadian rhythms, leaving patients feeling exhausted despite a full night’s rest.
A sensation of lightheadedness or imbalance, which may occur upon standing or with movement. Frequently linked to POTS, autonomic issues, or blood pressure dysregulation.
A sensation of not being able to get enough air, often worsened by exertion. It may occur alongside chest tightness or wheezing, and is commonly experienced during basic activities like walking or climbing stairs.
Describes cognitive issues like difficulty thinking clearly, poor memory, reduced mental stamina, and confusion. Patients often feel mentally slow or foggy and may find it difficult to focus on work, conversations, or reading.
The Long COVID Clinic website is intended for informational purposes only. It does not provide medical advice, diagnosis, or treatment. The content presented should not be relied upon as a substitute for professional medical guidance.
This platform offers a means to book an appointment with qualified healthcare professionals who can assess your condition in person. If you are experiencing a medical emergency or urgent symptoms, please call 999 or visit your nearest emergency department immediately.
Always consult a licensed medical practitioner for any concerns related to your health.
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