The proper sizing of a blood pressure cuff or how it’s wrapped around the arm can drastically change blood pressure measurements. You may have wondered if wrapping the cuff too tight makes a difference. Therefore, let’s answer the question, can a blood pressure cuff be too tight?
A blood pressure cuff is too tight if only one finger or less can be slipped between the cuff and the upper arm. A cuff secured too tight is caused using a cuff sized too small or a properly sized cuff pulled too tight. A cuff wrapped too tight can cause the BP measurement to be inaccurate.
Depending on the cause of the cuff being too tight, blood pressure measurements may be inaccurately high or low. This article will explain how each one of those false readings can occur. More importantly, I’ll inform you how to prevent it from happening.
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A Blood Pressure Cuff Too Tight
A blood pressure cuff can be too tight for two reasons:
- A correctly sized cuff was pulled too tight around the upper arm and secured.
- A cuff too small was pulled around the arm tightly because it is not long enough for the size of the upper arm.
Let’s tackle each one of these reasons and explain what happens in each situation.
A Correctly Sized Cuff Secured Too Tight
Assuming you have the proper sized cuff for your upper arm, it’s possible to secure it too tight or loose 1. The standard way to check if a cuff is secured properly is to slip your index and middle fingers under the lower edge of the cuff (between the cuff and the upper arm).
Therefore, let’s answer the question, how tight should a blood pressure cuff get?
Only two fingers should be able to fit snugly between the cuff and the upper arm. If more than two fingers fit underneath the cuff, then it is too loose. If only one or no fingers can fit snugly underneath the cuff, it’s too tight.
A Cuff Too Small Secured Tight
When a cuff is too small, it’s not long enough for the circumference of the upper arm. If it’s small enough, it may cause you to pull the cuff tighter than typical to secure the velcro so the cuff closes.
If the cuff is too tight, you won’t be able to slip two fingers between the cuff and the upper arm.
A tight BP cuff is one of 14 sections in my article about blood pressure cuffs. Learn more about BP cuffs, including how to apply them, errors made and sizes, here in the article, Blood Pressure Cuffs.
How A Blood Pressure Cuff Too Tight Affects Blood Pressure
Each one of the two reasons why a cuff may be too tight, affects the blood pressure measurement differently. One results in a higher blood pressure reading and the other one a lower reading. How is this possible? Let’s take a look.
When a cuff is the proper size but secured too tight, how does it affect blood pressure?
A properly sized cuff secured too tight results in an inaccurate blood pressure reading lower at the time of the measurement. The air bladder wraps more around the arm cutting off the blood flow faster causing a lower measurement.
The effect on blood pressure is similar to when a blood pressure cuff is too long for the arm. More of the upper arm is being squeezed than it should. The American Heart Association recommends a BP cuff bladder length of 75%-100% of the upper arm 2.
The bladder is the part of the cuff that fills with air. It’s sewn inside the outer material of the cuff and cannot be seen. Pulling the cuff too tight, squeezes the arm resulting in more of the bladder wrapping around the arm than if the cuff wasn’t pulled as tight 3.
I wrote an article about using a cuff too large. You can check it out right here, Blood Pressure Cuff Too Large.
My Own Blood Pressure Cuff Study
I wanted to conduct my own study about how my blood pressure was affected using my home monitor with a proper cuff size. First, I measured my blood pressure with the cuff wrapped with the proper tightness.
I measured my blood pressure three times to achieve accurate results. The following were my blood pressure measurements:
After resting for one minute, I immediately tightened the cuff too tight. I was barely able to slip one finger under the lower edge of the cuff. I measured my blood pressure three more times with the following results shown in the table below.
|BP With Proper Cuff Adjustment||BP With Cuff Too Tight|
The following were my average blood pressure readings:
- Proper Tightness: 117/71.3 mmHg
- Cuff Too Tight: 112.3/70.5 mmHg
After making the cuff too tight, the systolic blood pressure dropped almost 5 mmHg and diastolic almost dropped 1 mmHg. The results of my study confirmed the research saying blood pressure will measure lower when more of the arm circumference is squeezed by the cuff bladder.
A cuff secured too tight doesn’t always indicate a lower reading. Remember, the cuff used in my study is the correct size for my arm. If the cuff is too tight for a different reason, as discussed in the article’s next section, the measurement may be higher.
In addition, I noticed a difference in how my blood pressure monitor operated. It felt like it was struggling to inflate the cuff because it sounded not as loud and fast. This occurred because the air bladder was compressed more than typical making it more difficult to pump air into.
When A Cuff Too Small Is Secured too Tight, how does it affect blood pressure?
A BP cuff too small squeezing tightly increases BP. The cuff bladder doesn’t wrap around the upper arm as much as it should, making it more difficult to block the flow of blood in the artery. When the air pressure is released, the systolic pressure signal starts earlier which results in a higher BP measurement.
The air bladder inside the cuff should be at least 75% of the arm circumference 4. If the bladder isn’t long enough, it won’t cut off the blood flow properly when the cuff is inflating with air. In addition, if the cuff is too short, it may cause you to pull the cuff tighter than it should to secure it properly.
In a study evaluating cuff positioning, comparisons were conducted using a cuff too small for the upper arm. When the smaller cuff was used, systolic pressure increased 4.9 mmHg and diastolic pressure 4.0 mmHg 5.
I have an article, Blood Pressure Cuff Too Small, which dives into detail about the cuff being too small. It also discusses how obese arms is a major cause and how to correct it.
A Cuff Too Tight Causes Discomfort
If the tight cuff is too small for the upper arm, it will have to inflate longer to cut off the blood supply. The extra inflation and excess squeezing causes discomfort. Any discomfort during a measurement can cause the readings to be inaccurate 6.
For some people, including older and frail, the tightness of the cuff may exceed discomfort and cause pain 7.
A Cuff Too Tight Causing Bruising or Marks on the Skin
When I conducted my cuff too tight experiment described earlier in the article, when I removed the cuff, I noticed skin folds on my upper arm. This was caused by the extra pulling by the cuff causing the skin to crease and remain creased during the measurement.
Many people have asked, can a blood pressure cuff cause a bruise? A blood pressure cuff can cause a bruise if the cuff is pulled too tight or there’s repeated inflations over a short period of time. This typically occurs during surgical procedures or when the person is susceptible to bruising.
Red marks on the skin may occur from a tight cuff. A condition called petechiae, although rare, can occur at home from a tight cuff and repeated inflations of the cuff 8. If this happens, don’t assume it’s from the cuff. There may be a preexisting condition contributing to the cause.
You can find out those conditions in my article, Petechiae From A Blood Pressure Cuff.
Can a tight cuff increase blood pressure? A tight blood pressure cuff can cause an increase in blood pressure. This occurs if the tight cuff is too small, causes discomfort or if the air bladder wraps too much around the circumference of the upper arm.
Why does a blood pressure cuff pop off? A blood pressure cuff can pop off if it’s too tight or if the velcro has worn and is not securing the cuff properly when wrapped around the upper arm.
Why does a blood pressure cuff squeeze? A blood pressure cuff must squeeze the upper arm to cut off the blood flow in the brachial artery. This is necessary to hear the Korotkoff sounds of the blood flow when the cuff is deflated. The beginning and ending of the Korotkoff sounds signify the systolic and diastolic blood pressure measurements.
( Get my free Ebook which includes a breathing technique proven to lower BP 6 mmHg. Click the photo above or here for the free PDF )
Read Next – More BP Cuff Articles!
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