Claustrophobia can affect ordinary decisions in ways that other people barely notice. You might check whether a building has stairs before agreeing to visit, choose a particular train carriage because the doors feel easier to reach or postpone a medical scan because you cannot picture remaining inside the equipment.

For somebody else, the difficulty is more immediate. A door closes and attention moves straight towards the exit. The walls may suddenly feel closer, breathing feels different or the time until the space opens again becomes the only thing that seems important.

You may still complete the journey or appointment, but doing so does not tell us how much effort the experience required.

An enclosed situation can bring a quick physical response. You might notice:

• A racing heart, trembling or a rush of heat
• Tightness in the chest or a feeling that breathing has changed
• Dizziness, light-headedness or nausea
• Muscular tension or restlessness
• A strong urge to reach the exit or create more space

These sensations can become particularly frightening when leaving does not feel immediately possible.

A change in breathing may prompt the thought that there is not enough air, even when the environment is appropriately ventilated. The fear of the sensation can then increase attention to breathing further.

New, unexplained or persistent symptoms should not automatically be attributed to anxiety and may require appropriate medical assessment.

Different people can experience the same enclosed space very differently.

You may worry about:

• The doors not opening
• Becoming trapped
• Having a panic attack inside
• Feeling unable to breathe comfortably
• Being unable to leave when you choose
• Losing control in front of other people
• Nobody being able to help if something goes wrong

For some people, the most difficult thought is simply “I cannot get out right now.”

That can make situations such as a moving train or aircraft cabin difficult even when the space itself is relatively large.

Claustrophobia can influence how you arrange yourself within a space.

You might:

• Stand beside the lift doors
• Choose aisle seats
• Sit close to train or aircraft exits
• Check how windows or doors open
• Keep doors open whenever possible
• Take stairs instead of lifts
• Avoid tunnels, underground transport or enclosed parking areas
• Cancel or delay medical scans

Some of these are ordinary preferences. Choosing an aisle seat or taking the stairs is not automatically a problem.

The useful distinction is whether you are making the choice because you prefer it or because the alternative feels unavailable.

The practical cost of claustrophobia can be more revealing than the intensity of one anxious moment.

You might turn down work in a high-rise building because of the lifts, avoid a journey because of a tunnel or delay healthcare because a scan involves lying inside enclosed equipment.

Another person may still do everything they need to do but spend considerable time preparing, checking and recovering.

A useful question is:

What would I be doing differently if enclosed spaces felt more manageable?

Perhaps you would take the quicker route, attend the appointment, use the lift or sit wherever you wanted rather than wherever escape feels easiest.

Those everyday choices provide a clearer picture of what you want back.

You do not need to prove how small a space you can tolerate before asking for help.

One useful example is enough: which situation was difficult, what you expected would happen, what you noticed in your body, what you did to feel safer and what you would have preferred to do.

That gives treatment a practical direction.