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Mercy Dialysis Center
Understanding Your Dry Weight
What is dry weight?
Dry weight is your weight without any extra fluid. When you finish your dialysis
treatment, you should be at your dry weight.
Does dry weight stay the same?
Not usually. In an ideal world, if you did not gain or lose muscle/body weight,
your dry weight would stay the same. However, over time most people gain
or lose a little muscle/body weight. If you gain, this raises your dry weight.
If you lose, this will lower your dry weight.
How does the staff know what your dry weight is?
This is the tricky part. The dialysis team looks at several factors to decide
if you are gaining or losing dry weight. If you are eating well, you may
be gaining dry weight. If you have been ill or are eating poorly, you may
be losing dry weight. They also look at your blood pressure, how you are
breathing, and how you feel after treatment. These are all signs that your
dry weight might need to be changed.
Where does fluid come in?
The staff determines how much fluid to take off during a treatment by subtracting
your dry weight from the weight you come in for treatment. Example: A patient’s
dry weight is 70 kg. He/she comes in to treatment at 73 kg. The difference
is fluid – they will set the machine to take off 3 kg. When the patient
finishes treatment he/she will be at their dry weight (70 kg.).
What happens if dry weight isn’t adjusted?
If a patient gained body weight (muscle or fat), but dry weight has not been
adjusted, they will be dehydrated from removing too much fluid. Example #1:
The patient above gained body weight and now has a dry weight of 71 kg. If
the machine is set to take off fluid to a dry weight of 70 kg., (the patient’s
old weight), too much fluid will be taken off and he/she will become dehydrated.
He may cramp on the machine and will feel very weak and tired after treatment.
Example #2: If the above patient was ill and lost one kg. of body weight,
his new dry weight would be 69kg. If the machine was set at his old weight
of 70 kg., he will go home with an extra 1 kg. of fluid. This will make him/her
be short of breath and blood pressure may go up. He/she would also feel tired
and weak.
What else affects dry weight?
If a patient gains large amounts of fluid between treatments it is VERY difficult
for the staff to determine the correct dry weight. Is it body weight or is
it fluid? The symptoms of large fluid gains are the same as taking off too
much fluid: cramping on the machine, decrease in blood pressure, etc.
How can you help?
- Know what your dry weight is and tell the staff if you think your weight needs adjusting.
- Tell the staff how you are eating.
- Tell the staff how you’ve been feeling: Good? Sick? Dizzy? Unusually tired? Short of breath? Light headed? Falling at home? Anything unusual or different?
