What Does Asymptomatic Mean?

You may have heard your doctor describe a condition as "asymptomatic." The term literally means the absence of symptoms. For most diseases, there is an asymptomatic phase when the disease is present, but not producing symptoms.

What's important about this is, though you may feel fine, your body is not. And because you're unlikely to change your behaviors when you feel well, if what you have is transmissible, it's likely that you are passing it to others.

Screening tests are used to detect various conditions in those who are asymptomatic, allowing monitoring or early treatment. Unfortunately, many do not seek such an evaluation when they are asymptomatic because they are unaware of a reason to do so.

Asymptomatic Illnesses

An asymptomatic infection is one in which a bacteria, virus, fungus, or parasite has invaded the body but has not yet caused any symptoms (like fever or a cough).

Your body may fight off the invader and you may never know it was there. Or, you may develop symptoms of the illness after an asymptomatic phase. Depending on the pathogen, you may be able to spread the germs to others even though you have no symptoms.

A developing cancer may be asymptomatic for an extended period, growing and spreading until it begins to affect a body function and produce symptoms. Other conditions that may be asymptomatic during at least part of their course include high blood pressure (hypertension) and diabetes.

Once you have an illness or condition and have experienced symptoms, you may become asymptomatic during recovery or remission.

Some illnesses go through recurring cycles of being asymptomatic and then having a return of symptoms.

Detection

Depending on the concern, detection of asymptomatic illness may be done via a variety of testing methods (e.g., blood/sample tests, imaging). This may be done because of an awareness of risk factors or exposure, but some asymptomatic illnesses are missed when neither of these are relevant to a patient. They simply don't know there's reason to be screened.

The majority of cancer screening tests are designed to detect cancer when it is asymptomatic. Health screens, such as blood pressure and blood glucose, can detect issues like hypertension and diabetes before you experience symptoms.

An asymptomatic finding could also mean a subclinical infection. Examples are people without symptoms who have a positive test for strep throat, genital herpes, HIV, or hepatitis. Being aware of the asymptomatic infection could help reduce the spread of illnesses to others.

Treating a disease that has not yet shown any symptoms can make a difference in your long-term health or even survival. For example, controlling hypertension or diabetes can add years to your life. Removing polyps found during a screening colonoscopy can prevent the development of colon cancer.

Asymptomatic Findings

An asymptomatic condition could refer to any one of a number of different situations. It's often hard to know whether an asymptomatic condition will progress.

The finding of an asymptomatic condition could be an early sign, which if heeded, could improve your long-term quality of life or survival. An example of this would be the early detection of lung cancer on computed tomography (CT) screening.

On the other hand, the asymptomatic finding could be nothing—meaning that early detection will not lead to either an improved quality of life or greater survival. In this case, additional testing and medical interventions may be done unnecessarily.

Aside from the emotional upset this can cause, the work-up itself could pose risks (e.g., surgical risk from a biopsy). And overdiagnosis can lead to overtreatment and related side effects.

Overdiagnosis Controversy

There has been considerable controversy concerning the use of screening tests, even those for cancer. While colon cancer screening and lung cancer screening clearly save lives, it's still not certain whether prostate screening or even breast cancer screening plays a significant role in improving survival (weighing the benefits to some vs. risks to others).

Certainly, these screening tests increase the diagnosis of cancer but may lead to overdiagnosis. This is the root of disagreement surrounding PSA screening—it may result in unnecessary evaluations and harmful treatment for some, while improving survival for others.

Next Steps

There are situations in which treatment of an asymptomatic condition clearly makes a difference. Because of that, any asymptomatic finding needs to be carefully considered.The decision on whether to act should take into account not only what the finding is, but its medical implications, available treatments, your overall health, and other factors.

When talking to your doctor about how an asymptomatic finding should be interpreted and what (if anything) to do about this new information, ask a lot of questions.

Questions to Ask Your Doctor

  • What are the chances that I will develop the disease for which I'm now asymptomatic? How might that change with treatment?
  • What might treatment entail? What are the pros and cons?
  • What are the chances that nothing would happen if did nothing about the finding? (Sometimes looking at statistics is helpful.)
  • Is there concern that this condition is overdiagnosed?
  • What would you do if you were in my shoes?
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Article Sources
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  1. Aberle DR, Adams AM, Berg CD, et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med. 2011;365(5):395-409.  doi:10.1056/NEJMoa1102873

  2. Nielsen C. Six screening tests for adults: What's recommended? What's controversial?. Cleve Clin J Med. 2014;81(11):652-5.  doi:10.3949/ccjm.81gr.14003

  3. Martin RM, Donovan JL, Turner EL, et al. Effect of a Low-Intensity PSA-Based Screening Intervention on Prostate Cancer Mortality: The CAP Randomized Clinical Trial. JAMA. 2018;319(9):883-895.  doi:10.1001/jama.2018.0154

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