Hematocrit and Hemoglobin: Thick Blood Explained

Hematocrit and Hemoglobin: Thick Blood Explained

Hematocrit and hemoglobin are two of the most important numbers on a lifter's blood test. Together they show how many red blood cells you carry and how thick your blood is. Too high, and your blood flows more slowly, your heart has to work harder and the risk of a clot or a stroke goes up. Too low, and you feel tired, weak and out of breath.

Both are part of a standard blood count, cheap to test and easy to follow over time.

What they measure

• Hemoglobin (Hb): the protein inside red blood cells that carries oxygen.
  
• Hematocrit (Hct): the share of your blood that is made up of red blood cells. Swedish lab reports usually call it EVF.
  

The two usually move together. When one is high, the other tends to be high as well.

Units and normal ranges
Sweden, Norway and Denmark each report hemoglobin in a different unit, which confuses a lot of people when they compare numbers online. Typical reference ranges for adult men:

• Sweden: 134 to 170 g/L
  
• Norway: 13.4 to 17.0 g/dL
  
• Denmark: 8.3 to 10.5 mmol/L
  

For women the ranges are lower: about 117 to 153 g/L, 11.7 to 15.3 g/dL or 7.3 to 9.5 mmol/L.

Hematocrit is shown either as a fraction or as a percentage, so 0.45 and 45% mean the same thing. The usual range is about 0.40 to 0.50 for men and 0.35 to 0.46 for women.

These are typical values. Your lab report prints its own reference range next to each result, and that is the one to go by. Compare with your own earlier results as well.

What pushes the numbers up

• Dehydration: a test taken after a sauna, a long sweaty session or a night of drinking can read high without anything really being wrong.
  
• Testosterone and other AAS: they make the body produce more red blood cells. This is the most common reason lifters see high values.
  
• Smoking: carbon monoxide from smoke makes the body compensate with more red blood cells.
  
• Sleep apnea: low oxygen during the night has the same effect.
  
• A bone marrow condition: rare, and it has nothing to do with what you take. Only a doctor can rule it out.
  

How to get a fair reading

• Test in the morning after a normal night's sleep.
  
• Drink normally the day before and have a glass or two of water before you go.
  
• Skip the sauna and long, sweaty sessions the day before.
  
• Use the same lab and roughly the same time of day every time, so your results can be compared.
  

Reading your result

• Inside the reference range: fine. Keep testing at regular intervals and watch the trend.
  
• Just above the range: test again within a couple of weeks, well hydrated. If it is still high, book an appointment with a doctor.
  
• Hematocrit of 0.54 (54%) or higher: book an appointment with a doctor within a week or two instead of waiting for your next routine test. This is the level where doctors who prescribe testosterone step in.
  
• Any high value together with the clot signs below: emergency.
  

Watch the trend too. A hematocrit that climbs from 0.44 to 0.50 in two months tells you more than a single result of 0.50.

Symptoms of thick blood
Many people with high values feel nothing at all, which is why testing matters. Others notice:

• Headaches or a feeling of pressure in the head
  
• Dizziness
  
• A flushed, red face
  
• Itching after a hot shower
  
• Blurred vision
  
• Getting tired and out of breath more easily than usual
  

Signs of a clot
See a doctor the same day if one calf or leg is swollen, painful, warm or red. Call 112 at once (113 in Norway) for:

• Sudden shortness of breath or chest pain, especially pain that gets worse when you breathe in
  
• Coughing up blood
  
• A face drooping on one side, weakness in an arm or a leg, slurred speech or sudden confusion
  
• Sudden loss of vision in one eye
  

Bringing a high value down

• Talk to a doctor. They can check that nothing else is going on and, if it is needed, arrange a therapeutic blood draw (venesection) at a clinic.
  
• Do not use a blood bank to bring it down. Blood banks have strict rules about who may donate, and the blood goes to patients, so answer their health questions honestly.
  
• Never try to draw blood yourself.
  
• Drinking enough water fixes a reading that was falsely high from dehydration. It does not fix a value that is truly high.
  
• Get sleep apnea treated if you have it, and stop smoking.
  
• When the cause is something you take, the numbers usually fall back over the following weeks to months once you stop taking it. A doctor can follow that with you.
  

When the numbers are too low
Low hemoglobin (anemia) usually shows up as tiredness, pale skin, shortness of breath and poor performance in the gym. Common causes are low iron, blood loss and frequent blood donation. If your hemoglobin is below the range, ask for ferritin as well, which shows your iron stores, and see a doctor to find the cause. Black, sticky stools can mean bleeding in the stomach or gut and need a doctor the same day.

For advice the same day, call 1177 in Sweden or 116 117 in Norway. In Denmark, call your own doctor, or outside opening hours 1813 in the Capital Region or the lægevagt in your region.

Related reading
Bloodwork for Lifters covers when to test and what else to include. High hematocrit and high blood pressure often go together, so read the blood pressure guide as well.

Questions are welcome below. If you post your results, cover your name and ID number first.