1
,•An initial latent or ―silent‖ stage, in which no clinical signs are evident, characterizes some
diseases. In infectious diseases this stage may be referred to as the incubation period, which is
the time between exposure to the microorganism and the onset of signs or symptoms; it may last
for a day or so or may be prolonged, perhaps for days or weeks. Often the disease agent may be
communicable during this incubation period.
•The prodromal period comprises the time in the early development of a disease when one is
aware of a change in the body, but the signs are nonspecific; for example, fatigue, loss of
appetite, or headache. A sense of feeling threatened often develops in the early stage of
infections. Laboratory tests are negative during the prodromal period; thus it is difficult to
confirm a diagnosis.
•The manifestations of a disease are the clinical evidence or effects, the signs and symptoms, of
disease. These manifestations, such as redness and swelling, may be local, or found at the site of
the problem. Or signs and symptoms may be systemic, meaning they are general indicators of
illness, such as fever.
•Signs are objective indicators of disease that are obvious to someone other than the affected
individual. Examples of a sign are a fever or a skin rash.
•Symptoms are subjective feelings, such as pain or nausea. Both signs and symptoms are
significant in diagnosing a particular problem.
•Lesion is the term used to describe a specific local change in the tissue. Such a change may be
microscopic, as when liver cells are examined for pathologic change, or highly visible, such as a
blister or pimple observed on the skin.
,•A syndrome is a collection of signs and symptoms, often affecting more than one organ, that
usually occur together in response to a certain condition.
•Diagnostic tests are laboratory tests that assist in the diagnosis of a specific disease. The
appropriate tests are ordered on the basis of the patient's manifestations and medical history, the
clinical examination, and the patient's answers to specific questions. These tests may also be
used for monitoring the response to treatment or the progress of the disease. Such tests may
involve chemical analysis of body fluids such as blood, examination of tissues and cells from
specimens (e.g., biopsies or body secretions), identification of microorganisms in body fluids or
tissue specimens, or radiologic examination of the body. It is important that medical laboratories
have a Quality Assurance (QA) program in place to ensure accurate test results. Also, it is often
helpful for a patient to have any future or repeated tests done by the same laboratory to provide a
more accurate comparison of results.
•Remissions and exacerbations may mark the course or progress of a disease. During a
remission, the manifestations of the disease subside, whereas during an exacerbation the signs
increase. Rheumatoid arthritis typically has periods of remission when pain and swelling are
minimal, alternating with acute periods when swelling and pain are severe.
•A precipitating factor is a condition that triggers an acute episode, such as a seizure in an
individual with a seizure disorder. Note that a precipitating factor differs from a predisposing
factor. For example, a patient may be predisposed to coronary artery disease and angina because
of a high-cholesterol diet. An angina attack can be precipitated by shoveling snow on a very cold
day.
, •Complications are new secondary or additional problems that arise after the original disease
begins. For example, following a heart attack, a person may develop congestive heart failure, a
complication.
•Therapy or therapeutic interventions are treatment measures used to promote recovery or slow
the progress of a disease. These measures may include surgery, drugs, physiotherapy, alternative
therapies or behavior modification (see Chapter 3).
•Sequelae describe the potential unwanted outcomes of the primary condition, such as paralysis
following recovery from a stroke.
•Convalescence or rehabilitation is the period of recovery and return to the normal healthy state;
it may last for several days or months.
Systemic signs of disease
Include signs and symptoms common to significant infections in any area of the body. Fever,
fatigue and weakness, headache, and nausea are all commonly associated with infection.
Disease Prevention- (Primary prevention examples)
Primary Prevention
The goal is to protect healthy people from developing a disease or experiencing an injury in the
first place. For example:
•Education about good nutrition, the importance of regular exercise, and the dangers of tobacco,
alcohol, and other drugs
,•An initial latent or ―silent‖ stage, in which no clinical signs are evident, characterizes some
diseases. In infectious diseases this stage may be referred to as the incubation period, which is
the time between exposure to the microorganism and the onset of signs or symptoms; it may last
for a day or so or may be prolonged, perhaps for days or weeks. Often the disease agent may be
communicable during this incubation period.
•The prodromal period comprises the time in the early development of a disease when one is
aware of a change in the body, but the signs are nonspecific; for example, fatigue, loss of
appetite, or headache. A sense of feeling threatened often develops in the early stage of
infections. Laboratory tests are negative during the prodromal period; thus it is difficult to
confirm a diagnosis.
•The manifestations of a disease are the clinical evidence or effects, the signs and symptoms, of
disease. These manifestations, such as redness and swelling, may be local, or found at the site of
the problem. Or signs and symptoms may be systemic, meaning they are general indicators of
illness, such as fever.
•Signs are objective indicators of disease that are obvious to someone other than the affected
individual. Examples of a sign are a fever or a skin rash.
•Symptoms are subjective feelings, such as pain or nausea. Both signs and symptoms are
significant in diagnosing a particular problem.
•Lesion is the term used to describe a specific local change in the tissue. Such a change may be
microscopic, as when liver cells are examined for pathologic change, or highly visible, such as a
blister or pimple observed on the skin.
,•A syndrome is a collection of signs and symptoms, often affecting more than one organ, that
usually occur together in response to a certain condition.
•Diagnostic tests are laboratory tests that assist in the diagnosis of a specific disease. The
appropriate tests are ordered on the basis of the patient's manifestations and medical history, the
clinical examination, and the patient's answers to specific questions. These tests may also be
used for monitoring the response to treatment or the progress of the disease. Such tests may
involve chemical analysis of body fluids such as blood, examination of tissues and cells from
specimens (e.g., biopsies or body secretions), identification of microorganisms in body fluids or
tissue specimens, or radiologic examination of the body. It is important that medical laboratories
have a Quality Assurance (QA) program in place to ensure accurate test results. Also, it is often
helpful for a patient to have any future or repeated tests done by the same laboratory to provide a
more accurate comparison of results.
•Remissions and exacerbations may mark the course or progress of a disease. During a
remission, the manifestations of the disease subside, whereas during an exacerbation the signs
increase. Rheumatoid arthritis typically has periods of remission when pain and swelling are
minimal, alternating with acute periods when swelling and pain are severe.
•A precipitating factor is a condition that triggers an acute episode, such as a seizure in an
individual with a seizure disorder. Note that a precipitating factor differs from a predisposing
factor. For example, a patient may be predisposed to coronary artery disease and angina because
of a high-cholesterol diet. An angina attack can be precipitated by shoveling snow on a very cold
day.
, •Complications are new secondary or additional problems that arise after the original disease
begins. For example, following a heart attack, a person may develop congestive heart failure, a
complication.
•Therapy or therapeutic interventions are treatment measures used to promote recovery or slow
the progress of a disease. These measures may include surgery, drugs, physiotherapy, alternative
therapies or behavior modification (see Chapter 3).
•Sequelae describe the potential unwanted outcomes of the primary condition, such as paralysis
following recovery from a stroke.
•Convalescence or rehabilitation is the period of recovery and return to the normal healthy state;
it may last for several days or months.
Systemic signs of disease
Include signs and symptoms common to significant infections in any area of the body. Fever,
fatigue and weakness, headache, and nausea are all commonly associated with infection.
Disease Prevention- (Primary prevention examples)
Primary Prevention
The goal is to protect healthy people from developing a disease or experiencing an injury in the
first place. For example:
•Education about good nutrition, the importance of regular exercise, and the dangers of tobacco,
alcohol, and other drugs
