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Questions tagged [blood-tests]

Questions about tests of the blood that help to estimate the component(s) in it.

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26 votes
1 answer
6k views

Why are iron levels different in the left and right hands?

Yesterday I donated blood. When the nurse performed a finger prick test of iron using my left hand, she indicated that the level was too low. However, she then asked to perform the test again on my ...
Peter Flom's user avatar
12 votes
3 answers
10k views

Fasting blood glucose and Hemoglobin A1C not valid for athletes?

I've been a competing athlete, mostly in endurance sports for nearly 45 years now. As part of military and other physicals, I have had blood glucose levels come back several times with high levels, ...
JohnP's user avatar
  • 6,658
12 votes
2 answers
8k views

How long should a person keep blood test results?

If someone has no chronic health problems (but a family history of diabetes and high blood pressure), is there a good medical reason for them to keep their old blood test results that doctors have ...
Dan Getz's user avatar
  • 221
11 votes
1 answer
463 views

How does a MRSA test work?

Let's assume we have a patient with acute infection. The doctor suspects MRSA. A culture is taken, brought to the lab, and then what? I'm interested to hear what are the usual steps a laboratory ...
rumtscho's user avatar
  • 2,793
10 votes
1 answer
1k views

I have natural immunity to Hepatitis B. Do I pose risk to others?

Some time ago I was rejected as donor and received following rejection letter: Just wanted to inform you that there was a positive infectious disease result for Hepatitis B. Unfortunately, we ...
user19123129129's user avatar
10 votes
2 answers
273 views

How to detect cancer in general?

Can a common blood test spot cancer in general? Or is it necessary to take some specific tests for each kind of cancer?
Hugo Brito's user avatar
9 votes
1 answer
321 views

What causes elevated liver function tests in a young asymptomatic patient?

What are the possible causes and most probable causes of raised liver function tests (in particular AST and ALT) in an otherwise healthy, asymptomatic, young adult?
Kenshin's user avatar
  • 1,700
8 votes
2 answers
4k views

How does ones TSH tend to vary over the course of a day?

A single TSH (Thyroid Stimulating Hormone) blood test is commonly used to help diagnose thyroid problems, however my understanding is that the TSH tends to vary substantially over the course of a day, ...
Highly Irregular's user avatar
8 votes
1 answer
3k views

Is it possible to have an autoimmune disease and no C-reactive protein in blood serum?

Autoimmune diseases cause inflammation. C-reactive protein (CRP) should be elevated in a person with inflammation. Is it possible that a person with an autoimmune disease (e.g. autoimmune hemolytic ...
Hinko Pih Pih's user avatar
8 votes
2 answers
266 views

What blood tests are worth doing for a healthy 30-year-old male?

The patient is a 30-year-old male who seems healthy. The patient has to do a blood test for some administrative forms (namely, proof of immunity to rubella and varicella), and wonder what else could ...
Franck Dernoncourt's user avatar
8 votes
1 answer
198 views

Low dose and high dose dexamethason supression test

What is the difference between high dose and low dose dexamethason suppression test in Cushing Syndrome diagnosis?
S.Guazza's user avatar
8 votes
1 answer
135 views

How to find a good (or appropriate) doctor

General case What is the strategy you use to find a good / appropriate doctor? The current ones I know are: Randomness Mouth to mouth Reading online reviews Randomness gives... random results. ...
Sebastien Lorber's user avatar
7 votes
1 answer
87 views

Which of these things is needed for a first time pregnancy checkup?

My wife and I are now expecting our first child. She is 4 weeks and 7 days at the time of writing this. We are both under 30. I currently live in Dubai where I am British Expat and medical costing is ...
TheBlackBenzKid's user avatar
7 votes
1 answer
192 views

Why is prothrombin time not used to monitor the effects of heparin?

Unfractionated heparin (UFH) is an anticoagulant that main works "by inactivating thrombin and activated factor X (factor Xa) through an antithrombin (AT)-dependent mechanism". Prothrombin time (PT) ...
D.Tan's user avatar
  • 1,124
7 votes
2 answers
244 views

How accurate is testing for HSV-2?

I've never had any symptoms of a Herpes simplex virus 2 infection. However, I want to find out if I carry this type of virus in my body. Is it true that there is an antibody test to answer that ...
Peter's user avatar
  • 73
6 votes
1 answer
585 views

Why lower gauge needles aren't used to draw blood for blood tests?

I am told that lower gauge needles (broader needles) are used during blood donation to minimize the damage to the RBCs. If the probability of damaging the drawn RBCs is greater with Higher gauge ...
Zuch's user avatar
  • 135
6 votes
1 answer
193 views

What are the natural and healthy ways to increase blood sugar?

Some relatives of mine have low blood sugar. Doctor told them to eat table sugar whenever they get a feel of low blood sugar. AFAIK table sugar is not good for health. What are the natural and ...
Aquarius_Girl's user avatar
6 votes
1 answer
5k views

Why can't blood samples be taken from the legs/ankles as well arms/wrists?

This is a genuine question, which so far I've been unable to find an answer to. Some time ago when my wife was pregnant, she seemed to be constantly needing to have samples taken for various tests ...
user1751825's user avatar
6 votes
1 answer
109 views

How reliable is the determination method of reference ranges for blood tests?

A reference range is usually defined as the set of values 95 percent of the normal population falls within (that is, 95% prediction interval). It is determined by collecting data from vast numbers ...
Bob Ortiz's user avatar
  • 1,039
6 votes
2 answers
911 views

Why should I fast before taking blood tests?

This always puzzled me. Not only because it is a nuisance, but also because I cannot understand it. Whenever I have to take a blood sample to run some tests on it, I am always told not to eat ...
Luan Nico's user avatar
  • 163
6 votes
0 answers
130 views

Does the "Dawn Phenomenon" of blood sugar apply to non-diabetics?

I bought myself a $15 blood sugar testing kit the other day because I've been experiencing some health things that are rare for me such as migraines (I rarely have had headaches my entire life) and a ...
prediabetes's user avatar
5 votes
1 answer
140 views

Puncturing a vein vs. an artery

I was recently with my grandmother at the Emergency Department because she had difficulty breathing. After the clinical examination by a doctor, she received both an artery and a vein puncture. Why ...
Becky's user avatar
  • 115
5 votes
1 answer
4k views

Can eating chalk cause very low level haemoglobin level?

My friend has a haemoglobin level of 6 g/dl. She eats a lot of chalk. The doctor said that the chalk accumulation is hindering the production of haemoglobin. Does that make sense, or there might be a ...
user2808118's user avatar
5 votes
1 answer
221 views

What do these blood tests mean in general and why do doctors ask for them before taking action?

My doctor ordered some blood tests for me. I would like to understand what each test is for, meaning what information could be gathered from the results. W.B.C. Platelets E.S.R. C.R.P. Alpha feto ...
Ahmad Ali's user avatar
5 votes
1 answer
2k views

Does mastectomy permanently prevent using the arms for blood samples?

This question, Why can't blood samples be taken from the legs/ankles as well arms/wrists? , refers to Specimen Collection Procedure - PERFORMING A VENIPUNCTURE | Akron Children's Hospital, which says: ...
Ray Butterworth's user avatar
5 votes
1 answer
6k views

Are metamyelocytes typically present on blood tests?

Is it normal to have metamyelocytes present on a blood test result? Basically, does it adhere to the standard morphology of the WBC & platelet or is it indicative of something abnormal?
Butterfly and Bones's user avatar
5 votes
1 answer
343 views

High level of Vitamin D,1,25(OH)2, Total

I recently got blood test results and they say Normal Range, High level of Vitamin D,1,25(OH)2, Total = 18 - 72 pg/mL but my level is 96 I was researching this and found that it can be due to ...
Rhonda's user avatar
  • 561
5 votes
1 answer
94 views

Routine exams in patients with hypothyroidism

In people with hypothyroidism that is being treated with thyroid hormones and that are not showing symptoms or hypothyroidism, how often should these tests be performed: TSH blood test T4 blood test ...
YviDe's user avatar
  • 7,002
5 votes
1 answer
488 views

ABO blood type mismatch

I have a question about blood types and seeming hereditary contradictions. The above image of an Eldoncard blood test, which shows quite clearly that the testee has AB- type blood. (see image!). The ...
Henxan's user avatar
  • 51
5 votes
1 answer
525 views

Understanding the difference between IgG and IgE results

The following results are an example of an independent blood test and the differences between IgE and IgG. The bars in black are examples of IgE and those in grey IgG. If i use the example of ...
Motivated's user avatar
  • 171
5 votes
0 answers
5k views

What causes air bubbles/air glugs when getting blood drawn with a vacutainer system?

As I understand it, the vacutainer system used in modern phlebotomy should never result in air bubbles “glugging” into the vacutainer tube when blood is drawn from a patient. However, today I learned ...
RibaldEddie's user avatar
5 votes
0 answers
65 views

Blood tests for borrelia and their informative value

Disclaimer: I am here as a highly medically interested person looking for an explanation of an observed phenomenon, not for medical advice, as it is not about my person. I work in a diagnostic ...
Sam's user avatar
  • 51
4 votes
1 answer
102 views

Are medical units pertaining to blood-tests, etc. standard/universal? Or vary from country to country?

Are medical measurements/units pertaining to blood-tests and urine-tests standardized across the globe? Or are they different? (I thought the metric system was standard in science, but when I was ...
Pills N Pillows's user avatar
4 votes
1 answer
122 views

What are the online blood testing services that allow to pick and choose exactly what test you want?

I know there are now several competitive online blood test companies that offer a menu of bundled blood test services in the US. I am looking for a US based service that would disaggregate their ...
Sympa's user avatar
  • 759
4 votes
1 answer
4k views

When to take a blood test after a gout attack

Gout is caused by an elevated level of uric acid in the blood, which results in crystals forming in the joints. Once this reaches a critical level, the body responds by targeting the crystals, ...
Karnivaurus's user avatar
4 votes
1 answer
287 views

What are the likeliest causes for rising indirect bilirubin levels?

All the following data is from a task a professor gave me and is not connected to a true patient. Patient's bilirubin level is first 28 micromole/litre and direct bilirubin level is 8 micromole/litre. ...
Hinko Pih Pih's user avatar
4 votes
2 answers
409 views

What CGM systems don't require fingerstick calibration?

Most continuous glucose monitoring (CGM) systems require you to still do fingerstick blood testing on a daily basis in order to calibrate them. But that defeats the purpose of why people want CGM ...
Keshav Srinivasan's user avatar
4 votes
1 answer
73 views

Do Western Blot 'false negatives' eventually produce positives?

I've heard again and again that the Western Blot test, used to detect the presence of Lyme Disease, often produces false negatives. But I would suspect that at some point, whatever it is that Lyme ...
Manny Rodriguez's user avatar
4 votes
1 answer
61 views

What is the point in checking non-fasting glycemia?

I wonder what the point is in measuring the glucose level in a non-fasting blood test. Example (real case): Checking the fasting glycemia can amongst other things detect the presence of diabetes, ...
Franck Dernoncourt's user avatar
4 votes
1 answer
2k views

How many mL of blood is typically drawn for a HIV blood test?

I hope this isn't too broad or unanswerable a question but I'm wondering how many mL of blood serum are typically drawn out for a blood test for HIV. What's the minimum that's typically required?
user avatar
4 votes
0 answers
50 views

Does Blood Testing give meaningful insights in Vitamin/Mineral Deficiency?

I yesterday watched the documentary Vitamania by Dr Derek Muller, which is about the production, benefits and risks of vitamin supplements. In the film, he briefly talked about people being blood ...
Suimon's user avatar
  • 153
4 votes
0 answers
210 views

Can GFR be improved in patients with kidney failure?

How widely can glomerular filtration rate (GFR) values fluctuate and can they ever improve? How much "error" might one expect in the value if sampled quarterly?
gfrtoofar's user avatar
4 votes
0 answers
54 views

Is it worth testing regularly for oxidative stress?

I have read that oxidative stress is associated with neurodegenerative diseases, cardiovascular disease, ageing, cancer, and diabetes. Popular health 'buzz' would suggest consuming antioxidant ...
mgnb's user avatar
  • 213
3 votes
2 answers
934 views

Possible blood test after smoking weed

I'm going to a medical consultation early tomorrow (circa 5:45 AM) where might be a blood test. I was invited for a party tonight where I would drink and smoke marijuana (marijuana is illegal in my ...
Balint Bujtor's user avatar
3 votes
1 answer
557 views

Can superficial injury and exercise elevate AST and LDH levels?

Reading the information available here and here, it's stated that both exercise and other injuries can cause elevated results on a couple of indicators commonly used to measure liver function. ...
aroth's user avatar
  • 355
3 votes
1 answer
91 views

Can false positives/negatives be reliably detected by redoing the test?

As the title states, I'm wondering whether simply redoing a test is a valid means of eliminating the risk of a given result being false. The question is specifically about repeating the same exact ...
Wasabi's user avatar
  • 133
3 votes
1 answer
38 views

What approaches can I take to find out my blood type and Rhesus factor?

I need to find out my blood type and Rhesus factor. However, there is no medical necessity for this - it's just to know myself. (as such, I'm aware that medical insurance would likely not cover the ...
user14587's user avatar
3 votes
1 answer
519 views

Lab test result meaning

Why in this lab test results the microsomal antibodies amount has less sign and thireoglobulin antibodies don't have this sign? I did not question it first but now I have suspicion may be I am not ...
Sofiko's user avatar
  • 323
3 votes
1 answer
73 views

Who decides the "normal" values for blood count?

I'm currently researching the values for a Complete Blood Count. Obviously different sources give slightly different values, usually due to rounding, but I found that some values consistently shifted ...
JFBM's user avatar
  • 133
3 votes
2 answers
73 views

Is there any test to identify bacteria?

When I got some upper respiratory infection the doctor always prescribed broad-spectrum antibiotics like amoxicillin. Is there any test to identify bacteria, and if so, why doesn't the doctor order ...
Ryan's user avatar
  • 229