Why am I feeling fatigue and weakness after night shifts?

Question

Hello doctor,

I worked night shifts for the past four years and switched to a daytime schedule a few months back this year. Since then, I have been feeling nervous at times; my body feels weak and tired even after getting eight hours of sleep, and I also occasionally have difficulty speaking or feel a strange internal trembling.

Could this be due to a vitamin deficiency, hormonal imbalance, anxiety, or another underlying health problem?
What blood tests or other diagnostic investigations should I perform to determine the cause?

Kindly advise.

Answer 1

Hi,

Welcome to icliniq.com.

I read your query and understand your concerns.

This kind of cluster of symptoms after a shift pattern change is not rare. The body clock can take months to fully reset, but feeling weak and shaky and having speech difficulty is not something to brush off.

This could be a combination of factors, such as vitamin or mineral deficiency from irregular eating, hormonal readjustment, or even anxiety. It is also important to rule out any neurological issues. The probable causes are a mix of post-shift circadian rhythm disturbance, possible vitamin B12 or vitamin D deficiency, and stress-related anxiety.

To investigate further, the following tests would be useful:

CB (complete blood count).
Serum vitamin B12 and vitamin D.
Thyroid profile [thyroid-stimulating hormone (TSH) and free thyroxine (T4)].
Fasting blood sugar.
Electrolytes (sodium, potassium, calcium, and magnesium).
Liver and kidney function tests.
Baseline ECG (electrocardiogram).

If speech difficulty recurs, a neurology review and possibly an MRI (magnetic resonance imaging) of the brain should be considered based on specialist advice. The most likely working diagnosis is post-shift schedule fatigue with possible nutritional deficiency.

For now, the focus should be on regularizing sleep-wake timing, maintaining a balanced diet with adequate protein, staying well-hydrated, and incorporating light daily exercise. Limit caffeine intake and consider starting an over-the-counter multivitamin until test results are available. If symptoms persist or worsen, specialist input will be needed based on those results.

For follow-up, test results should be reviewed to narrow down the cause. Preventive measures include maintaining a fixed daily routine, avoiding skipped meals, getting short periods of sunlight exposure daily, and managing stress with relaxation techniques.

I hope this answers your query. Feel free to reach out anytime.

Thank you.