10 Medical Conditions That Mimic the Symptoms of Anxiety

Many medical conditions can mimic anxiety disorder symptoms, leading to a potential misdiagnosis.

Anxiety is a feeling of intense worry, nervousness, and fear. Anxiety disorders are common mental health conditions.

Certain medical conditions have similar symptoms to that of anxiety, for example, heart palpitations, shortness of breath, fatigue, and dizziness.

As a result, it’s possible to have one of these conditions and have it misdiagnosed as an anxiety disorder. It’s also possible to have an anxiety disorder along with one or more of these health conditions.

Postural orthostatic tachycardia syndrome (POTS)

An excessive increase in the heart rate when moving from lying down to standing up characterizes POTS. This can cause dizziness, lightheadedness, and palpitations, which are also common in anxiety disorders.

Why POTS mimics anxiety: Symptoms, like a rapid heartbeat, dizziness, and fatigue, can be mistaken for panic attacks or generalized anxiety.

Differentiating features: Changes in posture specifically trigger symptoms of POTS, and fainting or near-fainting episodes often accompany them. A tilt table test can help diagnose POTS.

Inappropriate sinus tachycardia (IST)

IST occurs when the heart rate is abnormally high without a clear cause. This can lead to sensations of a racing heart and palpitations.

Why IST mimics anxiety: The primary symptom of IST is a rapid heartbeat, which is also a common symptom of anxiety and panic attacks.

Differentiating features: IST involves a persistently high resting heart rate that doesn’t decrease with rest. Holter monitors or ECGs can help distinguish IST from anxiety-induced tachycardia.

Endometriosis

Endometriosis is a condition where tissue similar to the lining inside the uterus grows elsewhere in the body, causing pain and may lead to fertility issues.

Doctors may not only misdiagnose endometriosis as anxiety, but they may also mistake it for irritable bowel syndrome or heavy, painful periods. Anxiety disorders, depression, and other mental health conditions are common among people with endometriosis.

Why endometriosis mimics anxiety: Chronic pain and fatigue associated with endometriosis can lead to increased stress and anxiety-like symptoms.

Differentiating features: Endometriosis symptoms are often related to the menstrual cycle and can include severe pelvic pain, heavy periods, and pain during intercourse. A diagnosis typically involves pelvic exams and imaging studies.

Polycystic ovary syndrome (PCOS)

PCOS is a hormonal disorder causing enlarged ovaries with small cysts on the outer edges.

Anxiety disorders are also common among people with PCOS.

Why PCOS mimics anxiety: Hormonal imbalances can lead to mood changes, fatigue, and irritability, which are common in anxiety disorders.

Differentiating features: An important characteristic of PCOS is higher-than-usual testosterone levels, which can be determined via a blood test. Other PCOS symptoms include irregular menstrual cycles, excessive hair growth, acne, and weight gain.

Inflammatory bowel disease (IBD)

IBD is a group of conditions that involve chronic inflammation of the gastrointestinal tract. It includes conditions like Crohn’s disease and ulcerative colitis.

Why IBD mimics anxiety: Symptoms, like abdominal pain, cramping, and fatigue, can lead to significant stress and anxiety. Stomach pain can also be a symptom of anxiety.

Differentiating features: IBD symptoms often include chronic diarrhea, blood in the stool, and weight loss. To diagnose IBD, a healthcare professional may order a colonoscopy and imaging studies.

Hyperthyroidism

Hyperthyroidism, or an overactive thyroid, occurs when the thyroid gland produces excessive amounts of thyroid hormones, accelerating the body’s metabolism.

Why it mimics anxiety: Symptoms, like a rapid heartbeat, nervousness, and sweating, can be mistaken for anxiety.

Differentiating features: Hyperthyroidism often presents with physical symptoms, like tremors, unexplained weight loss, heat intolerance, and goiter — enlargement of the thyroid gland. Blood tests measuring thyroid hormone levels are crucial for diagnosis.

Adrenal insufficiency

Adrenal insufficiency, including Addison’s disease, is when the adrenal glands do not produce enough hormones, particularly cortisol.

Why adrenal insufficiency mimics anxiety: Symptoms, like fatigue, muscle weakness, and low blood pressure, can resemble those of anxiety and panic attacks.

Differentiating features: Adrenal insufficiency can cause salt cravings, weight loss, and hyperpigmentation, a darkening of the skin. Doctors use blood tests to measure cortisol and ACTH levels for diagnosis.

Ankylosing spondylitis (AS)

Also called Bechterew’s disease, AS is a type of arthritis that primarily affects the spine, leading to severe, chronic pain and stiffness.

Why AS mimics anxiety: The chronic pain and fatigue associated with AS can contribute to feelings of anxiety and stress.

Differentiating features: AS symptoms typically include back pain and stiffness that improves with exercise and worsens with rest. Imaging studies and genetic tests — known as HLA-B27 — can help a healthcare professional diagnose you with AS.

Lyme disease

Lyme disease is an infectious disease caused by the bacterium Borrelia burgdorferi. It’s transmitted through tick bites. Lyme disease can get progressively worse over time, especially if left untreated and unmanaged.

Why Lyme disease mimics anxiety: Many symptoms of Lyme disease, like fatigue, headaches, and cognitive difficulties, including a lack of concentration or “brain fog,” can be mistaken for anxiety or depression. Feelings of irritability and anxiety are common among people with Lyme disease.

Differentiating features: Lyme disease often has a characteristic bull’s-eye rash, joint pain, and flu-like symptoms. Blood tests for Lyme antibodies can confirm the diagnosis.

Fibromyalgia

Fibromyalgia is a chronic condition, and widespread musculoskeletal pain, fatigue, and tenderness in localized areas characterize it.

Why fibromyalgia mimics anxiety: The chronic pain and fatigue associated with fibromyalgia can lead to significant stress and anxiety. In fact, anxiety and depression are common symptoms of fibromyalgia. Traumatic events may also trigger fibromyalgia, as they can anxiety disorders.

Differentiating features: Fibromyalgia often affects specific, tender points on the body, as well as causing symptoms, like sleep disturbances and cognitive difficulties. To diagnose someone with fibromyalgia, a healthcare professional will usually rule out other causes and use specific criteria to assess your pain levels.

The bottom line

If you’ve been diagnosed with an anxiety disorder but suspect a different condition may be at play, it may be a good idea to seek a second opinion.

No matter what condition, or conditions, you may have, proper diagnosis and treatment can improve your quality of life. The correct diagnosis can be the first step in feeling better.

Sian Ferguson is a freelance health and cannabis writer based in Cape Town, South Africa. She’s passionate about empowering readers to take care of their mental and physical health through science-based, empathetically delivered information.