Many physical symptoms people attribute to anxiety, like a racing heart, sweating, shakiness, and trouble concentrating, can also be caused by treatable medical conditions. The overlap is so significant that even clinicians sometimes get it wrong. If your symptoms are new, worsening, or don’t respond to stress-management techniques, a medical cause is worth investigating before assuming it’s purely psychological.
The key to telling the difference usually comes down to a few patterns: whether your symptoms connect to specific thoughts and worries, whether they include physical signs that anxiety alone wouldn’t cause, and whether they follow a timeline that lines up with eating, sleeping, hormonal shifts, or substance use.
What Anxiety Actually Looks Like
Generalized anxiety disorder involves excessive worry occurring more days than not for at least six months, spanning multiple areas of life like work, health, or relationships. It’s not just feeling stressed about one specific thing. A clinical diagnosis requires at least three of these six physical symptoms: restlessness or feeling on edge, fatigue, difficulty concentrating or mind going blank, irritability, muscle tension, and sleep problems.
The hallmark of anxiety is that the physical symptoms are linked to the worry itself. Your heart races when you think about a deadline. Your stomach churns before a social event. The sensations follow the thoughts, and they tend to ease when the perceived threat passes or when you use coping strategies like deep breathing. If your physical symptoms seem to arrive out of nowhere, with no anxious thoughts preceding them, that’s a signal worth paying attention to.
A widely used screening tool called the GAD-7 scores anxiety severity on a 21-point scale: 0 to 4 is minimal, 5 to 9 is mild, 10 to 14 is moderate, and 15 or above is severe. It’s not a diagnosis, but it can help you and a clinician put numbers to what you’re experiencing and track whether it changes over time.
Thyroid Problems That Feel Like Anxiety
An overactive thyroid is one of the most common medical conditions misdiagnosed as anxiety. The overlap is striking: both cause restlessness, a racing heart, trembling, sweating, fatigue, difficulty concentrating, and disrupted sleep. In published case reports, patients have been treated for anxiety disorders for months before anyone checked their thyroid.
The distinguishing clues tend to be physical changes that anxiety doesn’t cause. Unintentional weight loss despite a normal or increased appetite is a major red flag. Fine tremors in both hands (visible when you hold your fingers out straight), heat intolerance, changes in bowel habits, and menstrual irregularities all point toward thyroid dysfunction rather than a mood disorder. In one documented case, a woman lost about 8 pounds in a single month while eating more than usual. Her anxiety-like symptoms resolved entirely once her thyroid hormone levels were brought back to normal with medication.
A simple blood test measuring thyroid hormone levels can confirm or rule this out. If you have anxiety symptoms plus unexplained weight changes or heat sensitivity, requesting a thyroid panel is reasonable.
Blood Sugar Drops That Mimic Panic
Reactive hypoglycemia, a drop in blood sugar that happens after eating, produces symptoms nearly identical to a panic attack: shakiness, sweating, heart palpitations, weakness, nausea, difficulty concentrating, and intense anxiety. The mechanism is straightforward. When blood sugar falls too low, your body releases a surge of adrenaline to compensate, and adrenaline is the same hormone responsible for the fight-or-flight response.
The timing is the giveaway. These episodes typically follow meals, especially meals high in refined carbohydrates or sugar. A large spike in blood sugar triggers a large insulin response, which can overshoot and send glucose levels crashing. If your “anxiety attacks” happen two to four hours after eating, improve when you eat something, and are worst when you skip meals, blood sugar is a likely contributor. One case study described a patient whose anxiety symptoms began at age 12 and were managed for years by eating a granola bar every hour. Her symptoms improved significantly with dietary changes that stabilized her blood sugar rather than with psychiatric medication.
Hormonal Shifts in Perimenopause
Women in their mid-40s to mid-50s who develop anxiety symptoms for the first time should consider hormonal changes as a factor. Perimenopause and menopause cause fluctuations in estrogen and progesterone that directly affect brain chemicals involved in mood regulation, including serotonin and GABA. Research on middle-aged Australian women found that menopause is linked to higher rates of anxiety and depression even in women with no prior history of either condition.
Anxiety symptoms during this stage often arrive alongside vasomotor symptoms like hot flashes, night sweats, and sleep disruption. If your anxiety appeared around the same time as these changes, it may be hormonally driven rather than a standalone anxiety disorder. The same hormonal influence on mood can also occur during other reproductive transitions, including the premenstrual phase and the postpartum period. Recognizing the pattern matters because hormonally driven anxiety may respond better to targeted hormonal approaches than to standard anxiety treatment alone.
Caffeine as a Hidden Trigger
Caffeine is a stimulant that acts on the same physiological pathways as anxiety. It increases heart rate, raises blood pressure, triggers jitteriness, and can cause racing thoughts and insomnia. According to UCLA Health, people who consume 400 milligrams or more of caffeine daily have a significantly higher risk of anxiety symptoms. That’s roughly four standard cups of brewed coffee, though energy drinks, pre-workout supplements, and certain teas can push your total higher than you realize.
If your anxiety symptoms are worst in the morning or afternoon (when caffeine intake peaks), improve on days you skip coffee, or started around the time you increased your intake, try cutting back for two weeks and see what changes. Caffeine-induced anxiety resolves when the caffeine is removed, which is the clearest way to distinguish it from an anxiety disorder.
Nutritional Deficiencies Worth Checking
Vitamin B12 deficiency can produce neuropsychiatric symptoms that look remarkably like anxiety: agitation, impaired concentration, insomnia, and apathy. B12 plays a critical role in nerve function, and when levels drop low enough, the nervous system doesn’t work properly. People at higher risk include vegans and vegetarians, older adults with reduced absorption, and anyone taking long-term acid-reducing medications.
B12 deficiency is diagnosed through blood tests. Standard serum B12 levels can sometimes miss early deficiency, so clinicians may also check related markers like methylmalonic acid and homocysteine for a more complete picture. The important point is that these symptoms are fully reversible with supplementation once the deficiency is identified.
Rare but Worth Knowing: Adrenal Tumors
A pheochromocytoma is a rare tumor of the adrenal gland that floods the body with adrenaline and related stress hormones. The classic symptom triad is headache, palpitations, and generalized sweating. These episodes can look exactly like severe panic attacks and often arrive in sudden bursts rather than as a constant baseline of worry.
In one published case, a patient received psychiatric treatment for anxiety for 13 years before the tumor was discovered. While this condition is uncommon, the pattern to watch for is episodes of intense physical symptoms (racing heart, pounding headache, drenching sweats) that spike suddenly, especially if accompanied by very high blood pressure readings during the episode. If your “panic attacks” include severe headaches and measurably elevated blood pressure, mention this specific combination to your doctor.
Patterns That Point Toward a Medical Cause
Across all of these conditions, a few common threads can help you sort out what’s going on:
- Physical symptoms without worried thoughts. In anxiety disorders, the mind drives the body. If your heart races or you tremble without any anxious thoughts preceding it, something physiological may be triggering the response.
- Symptoms tied to timing. Episodes that follow meals suggest blood sugar issues. Symptoms that worsen after coffee point to caffeine. New anxiety in your mid-40s alongside hot flashes suggests hormonal changes.
- Physical signs anxiety can’t explain. Unintentional weight loss, hand tremors at rest, heat intolerance, severe headaches during episodes, or measurably high blood pressure during a “panic attack” all warrant medical investigation.
- No response to anxiety treatment. If therapy, stress reduction, and lifestyle changes haven’t improved your symptoms, revisiting the diagnosis is appropriate.
A reasonable starting point is basic blood work: a thyroid panel, fasting glucose, and B12 level. These are inexpensive, widely available tests that can rule out several of the most common medical mimics in one visit. From there, your symptoms and history guide whether further testing makes sense.