Concentrated pee means that your urine contains more solutes such as salts and sugars and less water than normal.
Having concentrated pee can indicate dehydration or a need for your kidneys to conserve water.
Increase in urine concentration can be caused by glucose in your urine, heart failure, loss of body fluids, dehydration which can be caused by vomiting, excessive sweating, not drinking enough water or diarrhea.
Increase in urine concentration can also be caused by narrowing of your kidney artery also known as renal arterial stenosis.
The expected or normal range for urine-specific gravity is 1.0101 to 1.030.
Water's specific gravity is 1.
If your urine-specific gravity is lower than 1.0101, that means your pee has more water in it.
And if your urine-specific gravity is higher than 1.030, that means there are more waste products in your pee.
Urine or pee is most concentrated in the morning which can cause the urine or pee to be pale or straw color if you're hydrated well enough and healthy.
At bedtime or night your urine or pee should look as clear as water or at least pale yellow in color and if it doesn't then you need to drink more fluids.
If you drink a lot of fluid or water or other drinks, your pee should be clear to yellow.
And if you're dehydrated, your pee is usually darker yellow or slightly orange.
Other than how much fluid you drink, medication and foods can also affect the colors of your pee.
Although having pee that's red or dark brown may point to an underlying health condition.