How To Manage Your Fever Of Unknown Origin    read

Sep 29 2021


Fever is one of the most common causes of our distress. Sometimes it happens because of changing weather, other times medical conditions like malaria or typhoid lie behind it. But often, we cannot find the exact reason behind it. If your fever is of at least 38.3°C or 101°F and it stays for more than three weeks or occurs frequently with no obvious reasonor  noexact explanation or failure to reach a diagnosis despite of 1 week inpatient investigations , it is called the fever of unknown origin.

In this type of fever, even your physician can not tell the reason for the fever by looking at the symptoms. Hence, it becomes imperative to do diagnostic tests and know the possible reasons for fever. Mainly, there are four categories of potential aetiology of FUO centered of patient sub types of FUO:

  1. Classic: When the fever is caused by neoplasms, infections, and connective tissues affecting diseases.
  2. Nosocomial: When the fever is caused by pulmonary embolism, enterocolitis, deep vein thrombosis, and other similar diseases.
  3. Immune-deficient: When fever occurs to a person who has a compromised immune system.
  4. HIV-associated: When the fever is caused directly or indirectly by HIV.

As we have seen, these four types of fevers are classified on the basis of the reasons behind their origins. Along with reasons, the symptoms of these four types of fevers also might vary.

Possible Causes & Symptoms

Before you know how to manage a fever of unknown origin, it is important to know its symptoms and causes. Once the fever is properly diagnosed, it becomes easy to manage it.

As mentioned earlier, the types of FUOs are classified on the basis of the underlying cause. Doctors run a number of diagnostic tests to know the possible cause of the fever. A few common causes of FUOs are:

  • Infection causing medical conditions such as mononucleosis, Lyme disease, cat scratch fever, tuberculosis, etc.
  • Inflammations causing medical conditions such as rheumatoid arthritis, inflammatory bowel disease, and many others.
  • Malignant cancers such as lymphoma, leukemia, pancreatic carcinoma, and many other types of cancers.

Miscellaneous conditions such as abuse of drugs, hyperthyroidism, hepatitis, and various other reasons that can not be placed in any of the other categories.

The obvious symptom of fever is high temperature. For adults, it is more than 100.4°F while for children, it is more than 99.5°F. Other than that, some typical accompanying symptoms are headaches, chills, and sweating.

Doctors try to find the cause of FUO by looking for some non-typical symptoms like:

  • Sinus Congestion
  • Cough
  • Sore Throat
  • Rash

Managing Fever of Unknown Origin

When compared to other types of fevers, it is harder to manage the fever of unknown origin. Doctors can prescribe medicines that can temporarily lower the temperature but resolving the root cause of the problem is not possible most of the time.

That said, there are certain methods through which you can keep a check on your condition. These methods will also help you in making sure that your condition does not deteriorate further. Have a look at them:

  • Check out for other symptoms: The symptoms that accompany fever are the key to know the reason behind your condition. A raised temperature is common in every type of FUO but other different symptoms might reveal the cause of the problem. Hence, you should always keep a check on the symptoms other than high temperature.
  • Get diagnosis done: When the fever is caused by common diseases like cold and malaria, it gets easily diagnosed. But while finding the reason behind FUO, you might have to get a number of diagnostic tests done. Imaging tests, blood culture, urine culture, and various other types of tests are very common in diagnosing FUO. Do not be discouraged if you do not find any results from one or two tests. It might also be possible that you do not find any conclusive results at all.
  • Keep your doctor updated: In FUO, the body temperature gets higher than 101°F. If it reaches 102°F or 103°F, you should reach out to your doctor as soon as possible. Other than that, you should also consult your doctor if you are experiencing a new symptom.
  • Let the immune system work: In most cases of FUO, people get discharged without a conclusive diagnostic report. If your symptoms are manageable, you should let your immune system work and wait for the body to resolve FUO.

The Conclusion

Most people get worried about the constant high temperature since the causes of FUO are not easily known. But one should also keep in mind that FUO is very common and most people return to their normal health without getting a conclusive diagnosis.

Merely looking out for the symptoms, getting a few major diagnostic tests done, and keeping in touch with the doctor can help you manage the fever. And remember not to get excessively worried about the problem. Your immune system is going to do its best to resolve the condition by itself.


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