Why Am I tired?

9th February 2021 | Dr Boon Lim

Why am I exhausted?

If you have persistent pooling of blood in your lower body, your brain will keep activating your sympathetic nervous system to make your heart beat faster and more vigorously, and to start squeezing the vessels in your legs (vasoconstriction). If this is not corrected (for example, people with Ehlers-Danlos syndrome, or blood pooling that they can’t control) then the sympathetic nervous system can remain chronically activated. The main hormones involved in this response are adrenaline and noradrenaline which are essential to maintain blood pressure. However they also keep you in a persistent state of ‘fight or flight’ – which is beneficial if you need to run away acutely from a threat (the purpose of the sympathetic nervous system) but not appropriate for chronic situations in everyday modern life. Thus, whilst a short burst of this ‘fight or flight’ is helpful to navigate short term challenges in life, the constant ‘fight or flight’ response can leave you feeling anxious as if your body is primed and ready to respond to a threat – 24 hours a day.

‘Stress’ symptoms related to fainting

Associated symptoms can be panic attacks, tremors, and anxiety, insomnia, as well as exhaustion. You may also find yourself increasingly susceptible to picking up infections such as a common cold, tonsillitis or gastric virus, as your immunity weakens with chronic stress. In addition, chronic activation of the sympathetic nervous system may cause effects on your gut (including slower digestion, reflux, constipation), skin (acne, eczema, dermatitis), reproductive system (reduced sex drive and reduced fertility), shortness of breath, palpitations and headaches and lack of concentration.

These symptoms are invisible and not readily detected by basic examination and tests, so can often be misdiagnosed as anxiety.

How might stress worsen my fainting or pre-fainting symptoms?

In the same way, if you are feeling stressed or anxious, then your already activated sympathetic nervous system may be even more pronounced – so your heart beating fast and hard, anxiety and sweating may be quite severe.

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