# Important Standards of Human Health

### 1. PULSE RATE

Pulse rate, also known as heart rate, refers to the number of times the heart beats in one minute. It is a measure of the heart's rhythm and the rate at which it pumps blood throughout the body. The pulse rate is typically expressed in beats per minute (bpm).
For adults at rest, a normal pulse rate is usually between 60 and 100 beats per minute.
Measuring pulse rate can be done manually by placing fingers on the radial artery (located on the wrist, below the base of the thumb) or the carotid artery (located on the neck, on either side of the windpipe).

### 2. BLOOD PRESSURE

Blood pressure is the force exerted by the blood against the walls of the arteries as it circulates through the body.
Blood pressure is expressed using two numbers, typically measured in millimeters of mercury (mmHg):

1. Systolic Pressure: The higher number represents the pressure in the arteries when the heart contracts and pumps blood into the circulation. It is the peak pressure during each heartbeat.
2. Diastolic Pressure: The lower number represents the pressure in the arteries when the heart is at rest between beats and is filling with blood.

Blood pressure is monitored using a sphygmanometer. A measurement of 120/80 mmHg is considered normal blood pressure.

### 3. BODY MASS INDEX

Body Mass Index (BMI) is a numerical value that is calculated based on a person's weight and height. It is also known as the Quetelet Index, after its inventor, Adolphe Quetelet, a Belgian mathematician, astronomer, and statistician.
To calculate BMI, the following formula is used:
BMI = Weight (kg) / Height^2 (m^2), thus a person of height 1.75m and weight 70 kg would have a BMI of 70/(1.75x1.75) = 22.9

The following are the World Health Organization (WHO) classifications commonly used:

• Underweight: BMI less than 18.5
• Normal weight: BMI 18.5 to 24.9
• Overweight: BMI 25 to 29.9
• Obesity (Class 1): BMI 30 to 34.9
• Obesity (Class 2): BMI 35 to 39.9
• Extreme Obesity (Class 3): BMI 40 or higher

### 4. BODY TEMPERATURE

Body temperature refers to the degree of heat in the body, which is maintained within a narrow range to support normal physiological functions. Body temperature can be measured using various methods, including oral, axillary (armpit), tympanic (ear), and rectal thermometers.
The average normal body temperature for adults is generally considered to be around 98.6°F (37°C).
When the body is healthy and functioning normally, it regulates its temperature through a process called thermoregulation. The hypothalamus, a region in the brain, acts as the body's thermostat and helps maintain the core temperature within a relatively constant range.

Pyrexia: A higher body temperature, known as fever or pyrexia, is a common response to infections or illnesses. When the body detects pathogens (such as viruses or bacteria), it triggers the release of chemicals that raise the body's temperature to create an inhospitable environment for the invading microorganisms.

Hypothermia: A lower body temperature than the normal range is called hypothermia. It can occur due to prolonged exposure to cold temperatures or immersion in cold water. Hypothermia disrupts the body's ability to generate heat and maintain normal functions, leading to a potentially life-threatening condition if left untreated.

### 5. EYE SIGHT

A perfect eyesight, also known as 20/20 (or 6/6) vision, is a term used to describe normal visual acuity. It means that a person can see an object clearly from a distance of 20 feet (approximately 6 meters) that a person with normal vision should be able to see from the same distance.
Eyesight is tested on the Snellen Chart, which was developed by Dutch ophthalmologist Dr. Hermann Snellen in 1862. The Snellen chart, consists of multiple rows of letters or symbols, with each row progressively smaller than the one above it. The chart is typically displayed at a distance of 20 feet (6 meters) from the person being tested. During an eye examination, the person is asked to read the letters on the chart from a specific distance, and their ability to identify the letters at the appropriate size determines their visual acuity.

### 7. pH LEVEL

The body's pH balance is critical for maintaining proper physiological function. Many enzymes and biochemical processes in the body are sensitive to changes in pH, so the body tightly regulates blood pH to ensure optimal cellular function and overall health.
Blood pH is measured through a blood test called an arterial blood gas (ABG) analysis.
The normal pH level of human blood is slightly alkaline, with a narrow and tightly regulated range. The typical pH of arterial blood, which is commonly measured, is around 7.35 to 7.45. A pH value of 7 is considered neutral, values below 7 are acidic, and values above 7 are alkaline (basic).

### SUMMARY OF STANDARDS OF HEALTH

PhenomenonStandard Range
Pulse rate60 to 100 beats/min
Blood PressureSystolic – <120 mmHg
Diastolic – <80 mmHg
Body Mass Index (BMI) or Quetelet index20 to 25
below 20 – underweight
above 25 – overweight
Body temperature37°C (98.6°F)
pH level of human blood7.35 to 7.45
Eyesight6/6
Normal Cholesterol levelbelow 200mg/dL
Normal Haemoglobin levelMales – 13.8 to 17.2 gms/dL
Females – 12 to 15 gm/dL

Note: The information provided above is intended to be used as general knowledge for competitive examinations and not as any kind of medical reference.