Pyrexia is one of the commonest symptoms expressed by the patient in day to day clinical practice. Pyrexia is not a disease but manifestation of some hidden disease.While treating a case of Pyrexia, symptoms should be given the first priority rather than the cause, which can be correctly interpreted form Dr. W. Boericke’s statement “To let the characteristic Symptoms of the Individual patient, largely independent of the pathological nature of the case , be paramount in selecting the Remedy”. Diagnosis of the disease is also essential side by side with cause before administering a similimum medicine to the patient. Diagnosis helps to know the progress or extent, prognosis of the disease and thus helps us to select the further potency.

What is pyrexia?
      Pyrexia is the condition, which develops when the body temperature raises above 990 F (320 C). An increase in the diurnal variation of more than 150F. Normally : 980 F to 990 F ( normal body temperature) shows a diurnal variation of 1.50 F with an increase towards evening, reaching the peak between 6 pm and 10 pm.

What are the causes for pyrexia?
      Most commonly “Pyrogens” are said to be the “father of fever”. They are present mainly in the bacterial cell wall and mammalian tissues etc.
      Pyrogens enter our body in following ways.
      1. Infections : Bacterial, Viral, Ricketsial, Fungal, Parasitic etc.,
      2. Neoplasms : Fever may be present with any neoplasm but commonly with hypernephroma, lympho proliferate malignancies,             carcinoma of pancreas, lungs, bones and hepatoma.
      3. Vascular : Acute myocardial infarction, Pulmonary embolism., Pontine hemorrhage etc.,
      4. Traumatic : Crush injury.
      5. Immunological :
       a) Collagen disease, SLE, rheumatoid arthritis.
      b) Drug Fever.
      c) Serum Sickness.
      6. Endocrine : Thyrotoxicosis, Addison’s disease.
      7. Metabolic : Gout Porphyria, Acidosis, Dehydration.
      8. Hematological : Acute Hemolytic crisis.
      9. Physical Agent : Heat stroke, Radiation Sickness.
          When the cause is not ruled out it is labeled as PUO (Pyrexia of unknown origin)

What are the symptoms?
      Fever itself is a symptom of some hidden disease. But still, a patient suffering from fever may come with the following symptoms, but symptoms vary according to the disease:
      1. “ Chilly ” feeling,
      2. Rigors,
      3. Feeling of burning hot,
      4. Head ache,
      5. Restlessness and vague pain in the limbs and back,
      6. Malaise and weakness,
      7. Skin is not dry to touch,
      8. Pulse, Respiration rate are rapid,
      9. Anorexia,
      10. Tongue furred,
      11. Bowels Constipated,
      12. Urine scanty and highly coloured,
      13. In children vomiting and convulsion.