Understanding Vital Signs and Body Temperature

Vital Signs Overview

• Measurements of basic body functions are vital signs.
• Breathing, heart function, circulation, and body temperature are key indicators.
• Normal or abnormal body conditions can be determined by assessing vital signs.
• Body temperature, pulse rate/heart rate, respiration rate, and blood pressure are the four main vital signs.
• Blood pressure is often measured with the other vital signs, despite not always being considered one.
• "Signs of life" is another term for vital signs.
• Abnormal vital signs may point to health problems.

Body Temperature

• Body temperature indicates the amount of heat maintained by the body, which reflects its regulatory system.
• Body temperature is maintained through balancing heat loss and production.
• Normal adult body temperature is 37°C (98.6°F).
• Approximately 37.5°C (99.5°F) is the normal rectal or tympanic (ear) temperature.
• Around 36.4°C (97.6°F) is the normal axillary temperature.
• Body temperature is affected by factors such as the time of day, age, and emotional state.
• Core temperature, maintained by regulatory system, should be about 37°C.
• Core temperature is maintained through balancing heat loss and production.
• Normal body temperature ranges from 37.1°C to 37.7°C, or 97°F to 99°F.
• Fever (pyrexia) is indicated by a body temperature above 37.2°C (99°F).
• Body temperature below 35°C (95°F) is hypothermia.
• Sleep, cold exposure, or starvation can cause hypothermia.

Pulse Rate (Heart Rate)

• The pulse is the artery's repeated expansion and recoil caused by blood flow.
• Heartbeat frequency is reflected in the pulse.
• Heart rate (or pulse rate) is the number of heartbeats each minute.
• 60 to 100 beats per minute is the normal pulse rate for a healthy adult.
• The average pulse rate is 72 beats per minute.
• Exercise, strong emotions, pain, and illnesses can affect pulse rate.
• Assessments of pulse include rate, rhythm, and volume.
• The speed of the pulse is the rate.
• Whether the pulse is regular or irregular is the rhythm.
• Pulse volume is the strength of the pulse.
• Pulse can be felt with fingers where an artery is close to the surface and passes over a bone.
• Common pulse points are the radial, brachial, temporal, carotid, femoral, popliteal, posterior tibialis, and dorsalis pedis arteries.
• Adequate blood volume is indicated by a full pulse.
• Low blood volume is indicated by a thready pulse.

Respiration Rate

• Respiration is the process of breathing in oxygen and exhaling carbon dioxide.
• Metabolism and removal of carbon dioxide (a waste product) depends on it.
• The amount of breaths a person takes in a minute is the respiration rate.
• Normal respiration rate in adults ranges from 12 to 20 breaths per minute.
• Respiration rate above 24 breaths per minute is tachypnea.
• Respiration rate below 10 breaths per minute is bradypnea.
• Strong emotions, exercise, pain, and the environment can affect respiration rate.
• Apnea is the temporary stopping of breathing.
• Dyspnea is labored or difficult breathing.

Blood Pressure

• The force of blood against artery walls is measured by blood pressure.
• Systolic blood pressure measures pressure in arteries when the heart muscle contracts.
• Diastolic blood pressure measures pressure in arteries when the heart muscle rests between beats.
• Normal blood pressure for a healthy adult is 120/80 mm Hg.
• Pre-hypertension is systolic pressure between 120-139 mm Hg or diastolic pressure between 80-89 mm Hg.
• Consistently high blood pressure above 140/90 mm Hg is hypertension.
• Blood pressure can be impacted by factors like drugs, illnesses, and emotional state.
• Hypotension is low blood pressure, below 90/60 mm Hg.
• Low blood pressure can be caused by hemorrhage or systemic infection.
• Blood pressure can vary depending on the time of day.