Signs and symptoms
Signs and symptoms are diagnostic indications of an illness, injury, or condition. While signs are objective and externally observable, symptoms are a person's reported subjective experiences.
A sign, for example, can be an elevated or lower than normal temperature or blood pressure; or an abnormal finding showing on medical imaging. A symptom is something out of the ordinary that is experienced by an individual such as feeling feverish, a headache or other pains in the body. Symptoms can be a result of the immune system's response to an infection, the physical manifestation of an abnormal body condition, or the effect of a consumed substance. Symptoms, though often indicative of a disease process, are not always diagnostically relevant, and can be idiopathic in nature.
Signs and symptoms
Signs
A medical sign is an objective observable indication of a disease, injury, or medical condition that may be detected during a physical examination. These signs may be visible, such as a rash or bruise, or otherwise detectable such as by using a stethoscope or taking blood pressure. Medical signs, along with symptoms, help in forming a diagnosis. Some examples of signs are nail clubbing of either the fingernails or toenails or an abnormal gait.Symptoms
A symptom is something felt or experienced, such as pain or dizziness. Signs and symptoms are not mutually exclusive, for example a subjective feeling of fever can be noted as a sign by using a thermometer that registers a high reading. The CDC lists various diseases by their signs and symptoms such as for measles which includes a high fever, conjunctivitis, and cough, followed a few days later by the measles rash.Cardinal signs and symptoms
Cardinal signs and symptoms are very specific even to the point of being pathognomonic. A cardinal sign or cardinal symptom can also refer to the major sign or symptom of a disease. Abnormal reflexes can indicate problems with the nervous system. Signs and symptoms are also applied to physiological states outside the context of disease, as for example when referring to the signs and symptoms of pregnancy, or the symptoms of dehydration. Sometimes a disease may be present without showing any signs or symptoms when it is known as being asymptomatic. The disorder may be discovered through tests including scans. An infection may be asymptomatic but still be transmissible.Syndrome
Signs and symptoms are often non-specific, but some combinations can be suggestive of certain diagnoses, helping to narrow down what may be wrong. A particular set of characteristic signs and symptoms that may be associated with a disorder is known as a syndrome.Related terms
Symptomatic
When a disease is evidenced by symptoms it is known as symptomatic. There are many conditions including subclinical infections that display no symptoms, and these are termed asymptomatic.Signs and symptoms may be mild or severe, brief or longer-lasting when they may become reduced, or then recur known as a flare-up. A flare-up may show more severe symptoms.
The term chief complaint, also "presenting problem", is used to describe the initial concern of an individual when seeking medical help, and once this is clearly noted a history of the present illness may be taken. The symptom that ultimately leads to a diagnosis is called a cardinal symptom. Some symptoms can be misleading as a result of referred pain, where for example a pain in the right shoulder may be due to an inflamed gallbladder and not to presumed muscle strain.
Prodrome
Many diseases have an early prodromal stage where a few signs and symptoms may suggest the presence of a disorder before further specific symptoms may emerge. Measles for example has a prodromal presentation that includes a hacking cough, fever, and Koplik's spots in the mouth. Over half of migraine episodes have a prodromal phase. Schizophrenia has a notable prodromal stage, as has dementia.Nonspecific symptoms
Some symptoms are specific, that is, they are associated with a single, specific medical condition.Nonspecific symptoms, sometimes also called equivocal symptoms, are not specific to a particular condition. They include unexplained weight loss, headache, pain, fatigue, loss of appetite, night sweats, and malaise. A group of three particular nonspecific symptoms – fever, night sweats, and weight loss – over a period of six months are termed B symptoms associated with lymphoma and indicate a poor prognosis.
Other sub-types of symptoms include:
- constitutional or general symptoms, which affect general well-being or the whole body, such as a fever;
- concomitant symptoms, which are symptoms that occur at the same time as the primary symptom;
- prodromal symptoms, which are the first symptoms of a bigger set of problems;
- delayed symptoms, which happen some time after the trigger; and
- objective symptoms, which are symptoms whose existence can be observed and confirmed by a healthcare provider.
Vital signs
A digital application has been developed for use in clinical settings that measures three of the vital signs using just a smartphone, and has been approved by NHS England. The application is registered as Lifelight First, and Lifelight Home is under development for monitoring-use by people at home using just the camera on their smartphone or tablet. This will additionally measure oxygen saturation and atrial fibrillation. Other devices are then not needed.
Syndromes
Many conditions are indicated by a group of known signs, or signs and symptoms. These can be a group of three known as a triad; a group of four ; or a group of five.An example of a triad is Meltzer's triad presenting purpura, arthralgia, and myalgia. Meltzer's triad indicates the condition cryoglobulinemia. Huntington's disease is a neurodegenerative disease that is characterized by a triad of motor, cognitive, and psychiatric signs and symptoms. A large number of these groups that can be characteristic of a particular disease are known as a syndrome. Noonan syndrome for example, has a diagnostic set of unique facial and musculoskeletal features. Some syndromes such as nephrotic syndrome may have a number of underlying causes that are all related to diseases that affect the kidneys.
Sometimes a child or young adult may have symptoms suggestive of a genetic disorder that cannot be identified even after genetic testing. In such cases the term SWAN may be used. Often a diagnosis may be made at some future point when other more specific symptoms emerge but many cases may remain undiagnosed. The inability to diagnose may be due to a unique combination of symptoms or an overlap of conditions, or to the symptoms being atypical of a known disorder, or to the disorder being extremely rare.
It is possible that a person with a particular syndrome might not display every single one of the signs and/or symptoms that compose/define a syndrome.
Positive and negative
Sensory symptoms can also be described as positive symptoms, or as negative symptoms depending on whether the symptom is abnormally present such as tingling or itchiness, or abnormally absent such as loss of smell. The following terms are used for negative symptoms: hypoesthesia is a partial loss of sensitivity to moderate stimuli, such as pressure, touch, warmth, cold; Anesthesia is the complete loss of sensitivity to stronger stimuli, such as pinprick; Hypoalgesia is loss of sensation to painful stimuli.Symptoms are also grouped into negative and positive for some mental disorders such as schizophrenia. Positive symptoms are those that are present in the disorder and are not normally experienced by most individuals and reflect an excess or distortion of normal functions; examples are hallucinations, delusions, and bizarre behavior. Negative symptoms are functions that are normally found but that are diminished or absent, such as in apathy and anhedonia.
Dynamic and static
Dynamic symptoms are capable of change depending on circumstance, whereas static symptoms are fixed or unchanging regardless of circumstance. For example, the symptoms of exercise intolerance are dynamic as they are brought on by exercise, but are alleviated during rest. Fixed muscle weakness is a static symptom as the muscle will be weak regardless of exercise or rest.A majority of patients with metabolic myopathies have dynamic rather than static findings, typically experiencing exercise intolerance, muscle pain, and cramps with exercise rather than fixed weakness. Those with the metabolic myopathy of McArdle's disease and some individuals with phosphoglucomutase deficiency, initially experience exercise intolerance during mild to moderate aerobic exercise, but the symptoms alleviate after 6–10 minutes in what is known as "second wind".
Neuropsychiatric
Neuropsychiatric symptoms are present in many degenerative disorders including dementia, and Parkinson's disease. Symptoms commonly include apathy, anxiety, and depression. Neurological and psychiatric symptoms are also present in some genetic disorders such as Wilson's disease. Symptoms of executive dysfunction are often found in many disorders including schizophrenia and ADHD.Radiologic
s are abnormal medical findings on imaging scanning. These include the Mickey Mouse sign and the Golden S sign. When using imaging to find the cause of a complaint, another unrelated finding may be found known as an incidental finding.Cardinal
Cardinal signs and symptoms are those that may be diagnostic, and pathognomonic – of a certainty of diagnosis. Inflammation for example has a recognised group of cardinal signs and symptoms, as does exacerbations of chronic bronchitis, and Parkinson's disease.In contrast to a pathognomonic cardinal sign, the absence of a sign or symptom can often rule out a condition. This is known by the Latin term sine qua non. For example, the absence of known genetic mutations specific for a hereditary disease would rule out that disease. Another example is where the vaginal pH is less than 4.5, a diagnosis of bacterial vaginosis would be excluded.