Differential Diagnosis for Patient Feeling Fever but No Fever

• Single most likely diagnosis
  • Dehydration: This is a common condition where the body loses more fluids than it takes in, leading to symptoms such as feeling hot or feverish without an actual elevated body temperature.
• Other Likely diagnoses
  • Anxiety or Stress: Psychological factors can cause physical symptoms, including feeling feverish or hot without a fever.
  • Menopause or Perimenopause: Hormonal changes can lead to hot flashes, which might be perceived as feeling feverish.
  • Medication Side Effects: Certain medications can cause feelings of warmth or fever without an actual increase in body temperature.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Hypothyroidism: Although less common, untreated hypothyroidism can lead to serious health issues, and some patients might experience feelings of heat intolerance.
  • Adrenal Insufficiency: A rare but potentially life-threatening condition where the adrenal glands do not produce enough cortisol, which can lead to various symptoms including changes in body temperature perception.
  • Malignancy: Certain types of cancer can cause systemic symptoms, including feeling feverish without an actual fever.
• Rare diagnoses
  • Temporal Arteritis: An inflammation of the blood vessels in the head, which can cause fever-like symptoms among other issues.
  • Neurological Disorders: Certain conditions affecting the nervous system can alter the body's temperature regulation or perception, leading to feelings of fever without an actual increase in temperature.
  • Endocrine Disorders: Other than hypothyroidism, disorders like pheochromocytoma can cause episodic symptoms including feverish feelings due to the excessive release of catecholamines.