Several medical conditions produce symptoms nearly identical to a panic attack, including racing heart, chest pain, shortness of breath, dizziness, and a feeling of dread. Some of these are harmless, while others require urgent treatment. Knowing the differences can help you recognize when something other than anxiety might be driving your symptoms.
A panic attack itself involves an abrupt surge of intense fear that peaks within minutes and includes at least four physical symptoms: pounding heart, sweating, trembling, shortness of breath, chest pain, nausea, dizziness, chills or heat sensations, numbness or tingling, feelings of unreality, or fear of dying. That symptom list overlaps heavily with heart conditions, thyroid problems, seizures, and blood clots, which is exactly why so many people end up in the emergency room unsure of what just happened.
Anxiety Episodes vs. Panic Attacks
The most common experience confused with a panic attack is a severe anxiety episode. “Anxiety attack” isn’t a formal clinical term, but many people use it to describe intense worry that spills over into physical symptoms like a tight chest, rapid breathing, and a churning stomach. The key difference is how it starts: anxiety typically builds gradually in response to a specific stressor, while a true panic attack strikes suddenly and can come out of nowhere, sometimes even during sleep. If your symptoms ramp up over minutes to hours alongside a clear trigger, you’re likely dealing with acute anxiety rather than a panic attack.
Heart Rhythm Problems
Supraventricular tachycardia (SVT) is one of the most commonly misdiagnosed conditions in people told they have panic disorder. During an SVT episode, the heart races at 160 to 180 beats per minute due to a short circuit in its electrical system, not because of adrenaline. You feel a pounding heart, chest pressure, lightheadedness, and anxiety, which looks virtually identical to panic from the outside.
A few clues point toward a heart rhythm issue rather than anxiety. SVT produces an extremely regular, metronomic pounding sensation, while a panic-driven heart rate, though fast, keeps the normal electrical sequence and tends to feel slightly more variable. Some people with SVT notice visible pulsing in their neck. The episodes also tend to start and stop abruptly, like a light switch flipping, rather than building with a wave of fear. An electrocardiogram recorded during an episode can distinguish the two instantly, but the challenge is that symptoms are usually gone by the time you reach a clinic.
Thyroid Overactivity
An overactive thyroid floods the body with hormones that speed up metabolism, and the result can look remarkably like chronic panic: heart palpitations, trembling hands, sweating, shortness of breath, and a persistent sense of anxiety. One published case report described a patient initially diagnosed with generalized anxiety disorder who turned out to have hyperthyroidism. The psychiatric medications she received did nothing because the root cause was hormonal.
Physical signs that suggest thyroid trouble rather than an anxiety disorder include unexplained weight loss despite a normal or increased appetite, heat intolerance, changes in bowel habits, menstrual irregularities, and a fine tremor visible when you hold your hands out flat. A simple blood test measuring thyroid hormone levels can confirm or rule this out, and it’s one of the first tests typically ordered when someone presents with panic-like symptoms.
Adrenal Gland Tumors
A pheochromocytoma is a rare tumor of the adrenal gland that dumps surges of adrenaline and related hormones directly into the bloodstream. These surges produce sudden, intense episodes of high blood pressure, pounding headache, drenching sweat, and rapid heartbeat. The experience feels indistinguishable from a severe panic attack.
What makes pheochromocytoma different is the triad of headache, heavy sweating, and dangerously high blood pressure occurring together in discrete “spells.” Panic attacks can raise blood pressure, but not typically to the extremes seen with these tumors. The episodes may be triggered by physical exertion, certain foods, or even bending over. Because the condition is rare, it’s usually considered only after more common explanations have been excluded, but it’s important because it’s treatable once identified.
Pulmonary Embolism
A blood clot in the lungs causes sudden shortness of breath, chest pain, rapid heartbeat, and intense anxiety. The overlap with panic is so convincing that misdiagnosis has had fatal consequences. In one documented case, a 21-year-old woman hospitalized for another condition experienced repeated episodes of anxiety, rapid heart rate (up to 123 beats per minute), and fast breathing. Each episode was interpreted as a panic attack. She died, and an autopsy revealed a pulmonary embolism.
The chest pain from a blood clot tends to be sharp and stabbing, often located on one side of the chest, and it worsens when you breathe in deeply, cough, or twist your torso. Panic-related chest pain is more commonly a diffuse tightness or pressure. Oxygen levels drop in roughly 60% of pulmonary embolism cases, which doesn’t happen during a panic attack. Risk factors include recent surgery, prolonged immobility (like a long flight), use of hormonal birth control, or a history of blood clots. If you develop sudden one-sided chest pain with shortness of breath, especially alongside a swollen or painful leg, treat it as an emergency.
Focal Seizures
Seizures originating in the temporal lobe of the brain can produce fear, a racing heart, changes in skin color, tingling sensations, and a feeling of unreality, all without the convulsions most people associate with epilepsy. These episodes have been repeatedly mistaken for panic attacks, sometimes for years.
Published case reports illustrate how strange and varied these seizures can be. One patient’s episodes began with pins and needles in the head that spread to the torso and limbs. Another experienced hyperventilation, palpitations, one-sided facial tingling, and diminished hearing. A third initially noticed a smell like burning candles before later developing episodes of stomach discomfort, chest tightness, tingling in the extremities, and feelings of unreality. The presence of unusual sensory phenomena (phantom smells, one-sided tingling, hearing changes) or brief lapses in awareness during an episode are red flags that point toward seizure activity rather than panic. An EEG, which records brain electrical activity, can help make the distinction.
Vestibular Migraine
Vestibular migraines cause episodes of vertigo, dizziness, and unsteadiness that frequently trigger intense anxiety. Research has found that people with vestibular migraines are significantly more anxious and agoraphobic than migraine patients without balance symptoms, and the severity of their dizziness correlates directly with the severity of their headaches. The dizziness and disorientation can feel so alarming that many people develop panic-like responses to the episodes themselves, creating a feedback loop where the migraine triggers anxiety and the anxiety worsens the migraine symptoms.
If your “panic attacks” are consistently accompanied by a spinning sensation, sensitivity to head movement, or a headache that follows the episode, a vestibular migraine may be the underlying cause.
How These Conditions Are Sorted Out
When you show up with panic-like symptoms, the first priority is ruling out conditions that need immediate treatment. The standard workup typically includes blood tests to check thyroid function and other metabolic markers, along with an electrocardiogram to evaluate heart rhythm. Additional testing depends on the clinical picture: imaging of the lungs if a blood clot is suspected, an EEG if seizure-like features are present, or urine and blood tests for adrenaline-related hormones if episodes involve severe blood pressure spikes.
Panic disorder is what’s known as a diagnosis of exclusion for the physical conditions on this list. That doesn’t mean your symptoms aren’t real if the tests come back normal. Panic attacks are a genuine neurological event with measurable changes in heart rate, breathing, and stress hormones. But because so many serious conditions share the same symptoms, a thorough physical evaluation before settling on a purely anxiety-based explanation is worth pursuing, especially if your episodes include unusual features like one-sided symptoms, persistent high blood pressure, phantom sensory experiences, or chest pain that worsens with breathing.