Signs vs Symptoms

Signs and symptoms of a disease are confusing words for a non-medical layman and are mostly used interchangeably. These words have the same meaning but different features. Signs of any disease are observed by doctors or physicians, whereas symptoms are noticed by the patients themselves.

Physicians and health care professionals decide the disease of the patient by observing and diagnosing the patient’s body. In these measurements, they do blood tests, pulse rate, x-rays, take body temperature and in this way, reach the definite signs of the specific disease. Patients cannot diagnose conditions such as allergies, HIV, cancer, diabetes. These can be diagnosed only by medical experts. Signs are the physical demonstration of an individual’s body’s problems. But when the patient feels body pain, headache, muscle fatigue, these can be termed as symptoms.

Both signs and symptoms are beneficial in determining the diseases so that proper medication can be started. One is felt by the patient, and the other is diagnosed by the doctor.

Comparison Table

Basis for ComparisonSignsSymptoms
DefinitionA sign can be defined as the evidence of a disease observed by a doctor.A symptom can be defined as the evidence of a disease that felt a patient.
How to observeObserved by health care professionalsObserved by patients
Way to observeMedical devicesObserved by senses
TypesFour types:anamnestic signsPrognostic signsDiagnostic signsPathognomonic signsThree types:Chronic symptomsRelapsing symptomsRemitting symptoms
ExamplesHigh blood pressure, low or high sugar level, etc.Nausea, vomiting, headache, etc.

What are Signs?

Generally, a sign is a word that is used to indicate or provide information about something. In medical, this word is used by the health care professionals to get actual information about a particular disease by asking symptoms from the patients or by using measurable modes such as x-ray, blood test, and temperature. The most common sign is called “vital signs.” Vital signs include a patient’s breathing rate, heart rate, temperature, and blood pressure.

The signs are called the objective evidence of disease as they are observed by feeling, hearing, or seeing.  For example, fractures, swelling, and bleeding are signs. Signs are the physical characteristics of a disease. A range of devices is available to help doctors for identification and analyze the signs. These devices can detect the signs even not recognized by the patient. The stethoscope is used to listen to the sounds of the heart and lungs. A spirometer helps to measure lung function. Eye specialist uses Ophthalmoscope to examine the inside of the eye. X-ray imaging shows the damage of the bones. A sphygmomanometer is a device that fits around the arms and is used to measure blood pressure.


There are four types of medical signs; anamnestic signs, prognostic signs, diagnostic signs, and pathognomonic signs.

  • Anamnestic Signs: These signs refer to the part experience of the disease or condition. For example, skin scars may be evidence of previous severe acne. Similarly, paralysis stroke and heart attack are examples of anamnestic signs.
  • Prognostic Signs: These signs predict future disease. It means observing the signs and symptoms, and physicians predict the chances of occurrence of a disease.
  • Diagnostic Sign: These signs show the actual disease from which the person is suffering currently. For example, high levels of prostate-specific antigen in the blood of a male may be a sign of prostate cancer or a problem.
  • Pathognomonic Signs: It means that a doctor can link a sign to a condition with full certainty. For example, the presence of a specific microbe in a blood sample can point to a particular viral infection.

What are the Symptoms?

Symptoms are felt by the patients only. It is a type of report which is explained by the patient to the doctor. Based on symptoms, doctors further diagnose the diseases. Symptoms are termed as subjective evidence of the disease as they can only be felt by the person. Shivering, headache, nausea, muscle fatigue, and body ache are examples of the symptoms.

Symptoms are not visible to others and are considered as an indication of a particular disease. Symptoms should be taken seriously and should be consulted by the physicians. Some conditions show no symptoms at all. For example, a person can be suffering from high blood pressure for many years without knowing. Similarly, most cancers have no symptoms in the initial stages but show symptoms in aggressive steps. These are known as asymptomatic conditions. A disease without symptoms can be lethal.


There are three kinds of medical symptoms; chronic symptoms, relapsing symptoms, and remitting symptoms.
1. Chronic Symptoms: In this class of symptoms, there is a long-lasting pain that does not go away such as in cancer, asthma, diabetes and AIDs.

  • Relapsing Symptoms: These are the symptoms that reoccur after disappearing in the past—for example, multiple sclerosis and cancer. Symptoms of depression may not happen for years at a time but can then return.
  • Remitting Symptoms: Symptoms that get entirely escape from the body are called remitting symptoms. For example, symptoms of cold flue may occur for many days and then resolve without medicines.

Key Differences between Signs and Symptoms

  1. The signs are observed by the doctor, whereas symptoms are seen by the patient.
  2. Signs are visible, whereas symptoms are unclear and invisible.
  3. Signs are measured by medical devices, whereas symptoms cannot be measured instead of just felt.
  4. Signs are the subjective evidence of a disease, whereas symptoms are the objective evidence of disease.
  5. Signs can be of three types; anamnestic sign, prognostic sign, diagnostic sign, whereas symptoms can be of three kinds; chronic symptoms, relapsing symptoms, and remitting symptoms.
  6. Asthma, tuberculosis, AIDs, and cancer are the signs, whereas itching, headache, body ache, nausea are examples of symptoms.


In conclusion, signs and symptoms are interchangeable and confusing words for non-medical persons. These words are actually used by doctors and patients as clues to get proper information for medication and treatment.

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