Anxiety is a physiological event before it’s a psychological one. A substantial proportion of people presenting to primary care with physical symptoms are experiencing anxiety, and many of them don’t feel especially anxious — they feel unwell.
Knowing the mechanism doesn’t stop the symptoms. It does change what they mean, which turns out to matter more than it sounds.
The chest
Tightness, pressure, sharp catches. Usually intercostal muscle tension plus altered breathing. Anxious breathing is shallow and upper-chest, which overworks the accessory muscles and produces a genuine ache.
Anxiety-related chest pain is typically sharp, localised, positional, and tender when pressed. Cardiac pain is more typically pressure, unaffected by position, and worse with exertion. Get the first episode assessed regardless.
The stomach
Nausea, churning, urgency, appetite loss. The gut has its own nervous system and it’s heavily connected to the stress response — digestion is downregulated under threat, and blood is diverted away.
Irritable bowel syndrome and anxiety co-occur at high rates in both directions, and treating the anxiety often improves the gut symptoms considerably.
The throat
The sensation of a lump, or of not being able to swallow properly — globus. Muscle tension in the throat. Frightening, and physiologically benign. Persistent difficulty actually swallowing food is different and needs medical assessment.
The jaw, neck and shoulders
Sustained low-grade muscle tension, held for months. This produces real pain, tension headaches, and frequently dental problems from night-time clenching. Dentists spot anxiety earlier than doctors do, reasonably often.
The hands and face
Tingling and numbness, particularly around the mouth and in the fingers, are usually the result of over-breathing rather than a neurological problem. Lower carbon dioxide changes blood pH and affects nerve excitability — which is also where a good deal of the dizziness and unreality comes from.
The head
Tension headaches from muscle tightness. Dizziness and lightheadedness from breathing changes. Derealisation — the sense of being at one remove — which is one of the most frightening symptoms and one of the most benign.
The rule that keeps you safe
Get new or changed symptoms properly assessed once. Thyroid problems, arrhythmias, anaemia and medication side effects all masquerade as anxiety, and being told it’s anxiety when it isn’t is a real and common failure.
Then, once it has been settled, stop re-investigating — because repeated checking is what turns physical symptoms into health anxiety, which is a second problem on top of the first.