Symptom, Diagnosis and Dysfunction

A symptom (from Greek σύμπτωμα, "accident, misfortune, that which befalls",^[1] from συμπίπτω, "I befall", from συν- "together, with" and πίπτω, "I fall") is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality. A symptom is subjective,^[2] observed by the patient,^[3] and cannot be measured directly,^[4] whereas a sign is objectively observable. For example, paresthesia is a symptom (only the person experiencing it can directly observe their own tingling feeling), whereas erythema is a sign (anyone can confirm that the skin is redder than usual). Symptoms and signs are often nonspecific, but often combinations of them are at least suggestive of certain diagnoses.

Types of Symptoms 

1) Chronic, relapsing or remitting,  asymptomatic. 

2) Constitutional or general symptoms are those that are related to the systemic effects of a disease (e.g., fever, malaise, anorexia, and weight loss). They affect the entire body rather than a specific organ or location.

3) The terms "chief complaint", "presenting symptom", "iatrotropic symptom", or "presenting complaint" are used to describe the initial concern which brings a patient to a doctor. The symptom that ultimately leads to a diagnosis is called a "cardinal symptom".

4) Non-specific symptoms are those self-reported symptoms that do not indicate a specific disease process or involve an isolated body system. For example, fatigue is a feature of many acute and chronic medical conditions, whether physical or mental, and may be either a primary or secondary symptom. Fatigue is also a normal, healthy condition when experienced after exertion or at the end of a day.

5) Positive symptoms are symptoms that most individuals do not normally experience but are present in the disorder. It reflects an excess or distortion of normal functions (i.e., experiences and behaviours that have been added to a person’s normal way of functioning.^[8] Examples are hallucinations, delusions, and bizarre behavior.^[5]

6) Negative symptoms are functions that are normally found in healthy persons, but that are diminished or not present in affected persons. Thus, it is something that has disappeared from a person’s normal way of functioning.^[8] Examples are social withdrawal, apathy, inability to experience pleasure and defects in attention control.^[6]

Symptom versus Sign

A symptom can more simply be defined as any feature which is noticed by the patient. A sign is noticed by other people. It is not necessarily the nature of the sign or symptom which defines it, but who observes it.

A feature might be a sign or a symptom, or both, depending on the observer(s). For example, a skin rash may be noticed by either a healthcare professional as a sign, or by the patient as a symptom. When it is noticed by both, then the feature is both a sign and a symptom.

Some features, such as pain, can only be symptoms, because they cannot be directly observed by other people. Other features can only be signs, such as a blood cell count measured in a medical laboratory.

Source http://en.wikipedia.org/wiki/Symptom

DIAGNOSIS

Diagnosis is the process of identifying a disorder by examining its signs and symptoms, an identification of a disorder by such a process (Oxford Dictionary of Psychology, 2009).

A diagnosis is a label to a set of symptoms that tend to occur with one another (Hoeksema).  

The diagnosis of a psychological disorder requires evaluation by a trained mental‐health professional and usually an interview, administration of a variety of personality tests (and in some cases, neuropsychological tests), and gathering of background (including medical) information about the individual. The mental‐health professional arrives at a diagnosis by comparing this information to that in the Diagnostic and Statistical Manual of Mental Disorders (DSM), which uses a system devised by the American Psychiatric Association to classify psychological disorders (http://www.cliffsnotes.com/sciences/psychology/psychology/abnormal-psychology/diagnosis-of-psychological-disorders).

DYSFUNCTION

Dysfunction means abnormality or deviation from the norms of social behavior in a way regarded as maladaptive or impaired. 

It is a deficit in the ability to perform tasks. It is often a result of effects of symptoms but there is not always a direct correlation (Cara and MacRae, 2005).