What Is Hct In Blood Test

What Are Normal Hemoglobin Values

Normal hemoglobin values are related to the persons age and sex. Normal values may vary slightly between test systems, and which groups of doctors have determined normal values for their group of patients however, the value ranges are close for almost every group. An example of normal ranges that is widely accepted by Family Practice physicians is as follows:

• Birth: 13.5 to 24.0 g/dl
• Age < 1 month: 10.0 to 20.0 g/dl
• Age 1-2 months: 10.0 to 18.0 g/dl
• Age 2-6 months: 9.5 to 14.0 g/dl
• Age 0.5 to 2 years: 10.5 to 13.5 g/dl
• Age 2 to 6 years: 11.5 to 13.5 g/dl
• Age 6-12 years: 11.5 to 15.5 g/dl
• Age 12-18 years: 12.0 to 16.0 g/dl
• Age > 18 years: 12.1 to 15.1 g/dl

Underlying causes that are responsible for the anemia often produce other symptoms that are more specific to the underlying cause.

Reporting And Interpreting The Results

Your CBC test results are usually reported along with a reference range of expected or desired values to help guide your doctor in interpreting them. Reference ranges reflect the numeric values found in healthy people however, a small number of healthy people have values that are higher or lower than the ones shown in the reference range. Thus, values higher or lower than those in the reference range might or might not indicate a medical condition.

In addition to the reference range, your doctor will consider other factors when interpreting your CBC test results. These factors include your personal and family medical history, results from a physical exam, and other test results. Your doctor will also consider factors that might cause an incorrect test result such as improper sample collection or handling. Therefore, its important that you talk with your doctor about the meaning of your test results.

This brochure includes a brief description of the items included in the CBC test report. The descriptions can help you understand your results so you can have a more meaningful discussion with your doctor. Additionally, items in the CBC are summarized in the table at the end of this brochure for quick reference.

The Relationship Between Hematocrit Andhemoglobin

The following is a summary of the quantities/abbreviations thatare relevant when discussing hematocrit:

• Hct: Hematocrit
• ctHb: Concentration of total hemoglobin
• RBC: Red blood cell
• MCV: Mean cell volume
• MCHC: Mean corpuscular hemoglobin concentration

In normal conditions there is a linear relationship betweenhematocrit and the concentration of hemoglobin .An empirical study has shown that the relationship can beexpressed as follows:

Hematocrit can also be estimated from measurements of themean cell volume or the mean corpuscular hemoglobinconcentration :

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What Is An Average Hematocrit Level

35% 50% hematocrit level is considered normal in the case of a healthy adult. In the case of women, a hematocrit level between 36.1% 44.3% is considered normal, and in the case of men, a hematocrit level range between 40.7% 50.3% is considered normal. A hematocrit level between 32% 61% is average .

Hct tests are very reliable and usually pretty accurate for monitoring anemia. These tests aid medical practitioners in diagnosing the proper medical condition and advise the most suitable treatment. Some factors that are responsible for giving wrong and inaccurate hematocrit levels include:

• Blood transfusions that have taken place recently
• Hct levels are usually lower than usual when women are pregnant
• Hct levels are generally higher than normal for people living at a high altitude
• High hct levels are also caused by dehydration

Health practitioners very well know what factors could potentially skew hct test results. If some health conditions affect your hct results, your doctor might ask you to retake the test at a different time.

What To Do For Low Hematocrit Levels / How To Increase Hematocrit Levels

People with extremely low red blood cell counts may need to go to the doctor to get intravenous iron or blood transfusions. If theres an underlying health condition thats causing the body to produce less red blood cells, then medication might be needed to help stimulate the production of new red blood cells.

Some lifestyle changes can help increase red blood cell counts. Eating a variety of fresh, healthy foods that contain iron, vitamin B-12, and folic acid can prevent anemia. Taking these nutrients in supplement form can also be beneficial.

The best way to learn more about how to treat low or high hematocrit levels is to talk with your doctor or healthcare provider.

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How Blood Is Tested

Once your blood is collected, its placed in a centrifuge or an automated hematology analyzer instrument.

The centrifuge separates the red blood cells from the plasma , white blood cells, and platelets, giving a direct measure of the percentage of RBCs in the blood sample.

Automated instruments determine the hematocrit through several methods. Some instruments measure/count cells through electrical impedance , some measure/count cells with a laser beam, and some measure/count cells by adding fluorescent reagents. Whichever method is used, the hematocrit is calculated from the RBC cell count , mean cell volume , and the total sample volume .

How To Increase Hematocrit

If you show signs of low Hct and need to increase hematocrit, then there are a number of ways you can do this naturally.

Its important to remember that the following methods are not ways to treat chronically low hematocrit, but ways to improve your cardiovascular health and address any nutritional deficiencies.

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Dangerously Low Hemoglobin Levels

Some people show signs of hemoglobin levels that are dangerously low. The causes of low hemoglobin that can put your life at risk could be due to heavy blood loss, RBCs getting destroyed too quickly, or major problems in your organs.

The journal Critical Care reports that critically low levels of hemoglobin are generally classed as anything below 8 g/dL or 8.5 g/dL.

When hemoglobin levels fall so low, doctors may have to put off surgery and raise hemoglobin levels. In critical cases, doctors may have to order a blood transfusion to increase levels of hemoglobin.7

However, some doctors say that, in some cases, the trigger point for a blood transfusion could be a low as 7.0 g/dL.

How Is A Cbc Done

If the CBC is the only blood test youâre having, you can eat and drink like you usually would.

Your part of the test is simple and takes just a few minutes. A nurse or lab tech will take a sample of blood by putting a needle into a vein in your arm. Afterward, you can leave and get back to your routine. Theyâll send the blood to a lab for review.

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Hematocrit Blood Test: Low Or High Hct Levels Meaning

If you show symptoms of anemia , irritation, dizziness, constant headaches, and heavy periods, your doctor might want to carry out a blood test. A hematocrit test is a blood test that medical professionals undertake to diagnose health conditions like anemia and other related issues. The hematocrit test allows medical practitioners to make the correct diagnosis and recommend the proper treatment.

The present article highlights and describes hematocrit tests and what low hct and high hct mean.

When To Get Tested:

• when you have signs and symptoms of anemia .
• when you have signs and symptoms of polycythemia
• At regular intervals to monitor a disorder that affects RBCs and to evaluate the effectiveness of treatment

Sample Required:

• The patient blood is taken in EDTA.
• It is stable for 48 hours at 4 °C and 6 hours at 23 °C.
• Fetal blood: Collected by percutaneous blood sampling.

Precautions for Sample:

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The Components Of Whole Blood

Whole blood is comprised of erythrocytes , platelets and leukocytes. The cells are suspended in the aqueous medium ofplasma.

In blood from healthy individuals, erythrocytesconstitute the vast majority of cells the erythrocytes containhemoglobin , which gives blood its red color and which hasoxygen-binding abilities. Plasma mainly consists of water but also of salts, various proteins and lipidsas well as other constituents, e.g. glucose.

FIG. 1. A centrifugated whole-bloodsample

The definition of hematocrit is the ratioof the volume of packed red blood cells to the total bloodvolume and is therefore also known as the packed cell volume,or PCV.

The hematocrit is reported as a percentage or a ratio.In healthy adult individuals the red blood cells constituteapprox. 40-48 %, whereas newborns may have hematocrits of up to60 % .

The layer between the RBCs and plasma, the buffy coatlayer, constitutes approx. 1 %. It consists of WBCs andplatelets and should therefore not be calculated as part of thepacked cell volume.

Platelets Helping To Clot Blood

Platelets are the smallest blood cells. They are an important part of blood clotting. These small cells clump together and form a sticky mass that helps the blood to clot. Blood clots help your body handle injury by stopping or preventing bleeding. Blood clots can also cause problems, however, when they occur within the blood vessels or the heart such clots cause a blockage known as thrombosis.

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The Differential Visualizing The Cells

When performing a differential, a medical technologist looks at the various cells under a microscope. A differential provides information about the relative numbers of each type of WBC. Such information helps the doctor determine whether an illness is caused by a bacteria, a virus, or leukemia. A differential can be used to monitor patients with allergies and to determine how a patient is recovering from an illness or responding to therapy.

In addition to the cell types listed previously, certain cell types that dont normally appear in the blood can be reported in the differential. These cells include promyelocytes, metamyelocytes, blasts, etc. Presence of any of these cells indicates a need for follow-up with your doctor.Finally, the differential can provide information about the appearance of RBCs, since the cells are visualized under a microscope. The appearance of RBCs helps differentiate the various types of anemia.

How To Lower Hematocrit Levels / What To Do For High Hematocrit Levels

If your hematocrit value is high, it is important to work with your doctor to find out why and to treat any underlying conditions. You may be able to reduce your hematocrit level by the following diet and lifestyle changes:

• Avoiding iron supplements
• Moderate exercise

Some patients with very high hematocrit levels may require more serious medical intervention or drug therapy. Always follow the treatment plan prescribed by your doctor.

Other than lifestyle changes, your doctor may prescribe a medication to help with high hematocrit levels. Blood clot medications are commonly prescribed because people with too many red blood cells have a higher risk of getting a blood clot. Aspirin is sometimes recommended by doctors because of its ability to help with blood clots.

Other medications that doctors prescribe for high hematocrit levels are likely to focus on treating the condition thats causing the body to produce too many red blood cells, like bone marrow or heart disease. Phlebotomy is a popular way to control high red blood cell counts. In phlebotomy, blood is taken from the veins to make it thinner.

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Why Are Hematocrit Levels Important

Hematocrit tests can tell doctors if someone is anemic, which is one of the most common reasons for ordering the test. Symptoms of anemia include tiredness, grumpiness, heavy menstrual periods, cold hands and feet, and poor concentration. Your doctor may ask you to get a hematocrit test done if you have any of those symptoms.

Hematocrit tests, which are sometimes called packed cell volume tests , can also help tell doctors whether someone has other nutritional deficiencies or health problems such as leukemia, kidney disease, or arthritis. Hematocrit tests are important because they measure how many red blood cells someone has. Too many or too few red blood cells can indicate certain nutritional deficiencies or diseases that doctors will know how to identify.

Calculation Of Hematocrit From Hemoglobin

As there is a linear relationship betweenhemoglobin and hematocrit as described earlier,it is possible to calculate the hematocrit on analyzers thatmeasure hemoglobin. When making this conversion, two factorsshould be taken into consideration:

• The analytical quality of the ctHb measurement
• The precision of the equation that converts the two parameters

The measurement of ctHb from most good-qualityanalyzers is usually reliable however, the equations used tocalculate the hematocrit vary from analyzer to analyzer. Someanalyzers use an empirically found equation whereasothers use an approximate conversion factor of 3 .

Example:

TABLE I: Effect of different conversion factors onHct %.* Conversion factor: g/dL × 0.62058 = mmol/L

Limitations:

• It is generally assumed that the conversion from hemoglobin to hematocrit is straightforward since most methods measuring ctHb are considered to be fairly accurate however, different analyzers use different conversion factors, which may compromise the reliability of the hematocrit result. Hematocrit and hemoglobin are often used interchangeably however, different studies have shown that the two parameters are not comparable, but that they have their separate applications .

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What Is A Normal Hematocrit Ranges By Ages

The normal ranges for hematocrit are depended on the age after adolescence and the sex of the individual. The normal hematocrit ranges by age chart are shown here:

• ANED: Alive no evidence of disease. The patient arrived in the ER alive with no evidence of disease.
• ARF: Acute renal failure
• CPAP: Continuous positive airway pressure. A treatment for sleep apnea.
• DJD: Degenerative joint disease. Another term for osteoarthritis.
• DM: Diabetes mellitus. Type 1 and type 2 diabetes
• IBD: Inflammatory bowel disease. A name for two disorders of the gastrointestinal tract, Crohn’s disease and ulcerative colitis
• p.o.: By mouth. From the Latin terminology per os.
• q.i.d.: Four times daily. As in taking a medicine four times daily.
• RA: Rheumatoid arthritis
• SOB: Shortness of breath.
• T: Temperature. Temperature is recorded as part of the physical examination. It is one of the “vital signs.”

Drugs That Reduce Levels

Some drugs may reduce your hematocrit value if you are already taking them for some other health condition, but never start taking them or increase your dose for this purpose. Always follow the treatment plan prescribed by your doctor.

Drugs for mountain sickness, polycythemia vera , type 2 diabetes, male contraception, and malaria can reduce hematocrit .

Hematocrit can also be reduced as a result of taking:

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What Do The Results Mean

Your hematocrit test results are reported as a number. That number is the percentage of your blood that’s made of red blood cells. For example, if your hematocrit test result is 42, it means that 42% of your blood is red blood cells and the rest is white blood cells, platelets, and blood plasma.

A hematocrit level that’s lower than normal may be a sign that:

• Your body doesn’t have enough red blood cells . There are many types of anemia that can be caused by different medical conditions.
• Your body is making too many white blood cells, which may be caused by:
• Certain cancers, including leukemia, lymphoma, multiple myeloma, or cancers that spread to the bone marrow from other parts of the body

A hematocrit level that’s higher than normal may be a sign that:

• Your body is making too many red blood cells, which may be caused by:

If your results are not in the normal range, it doesn’t always mean that you have a medical condition that needs treatment. Living at high altitudes where there’s less oxygen in the air may cause a high hematocrit. That’s because your body responds to low oxygen levels by making more red blood cells so that you get the oxygen you need.

Pregnancy can cause a low hematocrit. That’s because the body has more fluid than normal during pregnancy, which decreases the percentage that’s made of red blood cells.

Why Do Doctors Measure Hematocrit

As with hemoglobin, normal hematocrit ranges depend on age and gender, and the normal range may vary by the specific test used. Normal hematocrit levels are:

• Newborns: 55% to 68%
• One week of age: 47% to 65%
• One month of age: 37% to 49%
• Three months of age: 30% to 36%
• One year of age: 29% to 41%
• Ten years of age: 36% to 40%
• Adult males: 42% to 54%
• Adult women: 38% to 46%

Just as low hemoglobin levels signify anemia, a person with a low hematocrit percentage is also anemic. High hematocrit percentages are seen in the same populations that may have high hemoglobin levels.

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How Do Changes In Haematocrit Affect Health And Wellbeing

The haematocrit percentage indicates the amount of space within the blood that is occupied by red blood cells. Therefore, a low haematocrit suggests there are too few red blood cells being produced, while an increased haematocrit reading indicates there are too many red blood cells in circulation. Because the haemoglobin in red blood cells has an important function in transporting gases to and from the body, a fluctuation in red blood cell levels can affect our health.

For example, a low haematocrit usually signals an individual has anaemia, a condition where your body doesnt have enough red blood cells or haemoglobin to meet the needs of the body.

Equally, polycythaemia occurs when the bone marrow overproduces red blood cells of its own accord.