NURS 6501 :Explain the pathophysiology of the three P’s for (polyuria, polydipsia, polyphagia)” with the given diagnosis of Type I DM.
Scenario 2: Type 1 Diabetes
A 14-year-old girl is brought to the pediatrician’s office by his parents who are
concerned about their daughter’s weight loss despite eating more, frequent
urination, unquenchable thirst, and fatigue that is interfering with her school
activities. She had been seemingly healthy until about 4 months ago when her
parents started noticing these symptoms. She admits to sleeping more and gets
tired very easily.
FH:- maternal uncle with “some kind of sugar diabetes problem” but
parents unclear on the exact disease process
SH: denies alcohol, tobacco or illicit drug use. Not sexually active.
Labs: random glucose 244 mg/dl.
DIAGNOSIS: Diabetes Mellitus type 1 and refers to an endocrinologist for further
work up and management plan.
1. Explain the pathophysiology of the three P’s for (polyuria, polydipsia,
polyphagia)” with the given diagnosis of Type I DM.
Diabetes type 1 is also known as juvenile diabetes and is dependent on
insulin injections. Type 1 diabetes happens when the pancreas does not
produce enough or any of the insulin hormones in the body, which are
necessary to help regulate the glucose in the body. Common signs and
symptoms of type 1 DM can appear relatively suddenly. These symptoms
include; increased thirst(polydipsia), frequent urination (polyuria), bed-
wetting in children who previously did not wet the bed during the night,
extreme hunger (polyphagia), and unintended weight loss, irritability and
other mood changes, fatigue, weakness, and blurred vision.
Pathophysiology of Polyuria
Polyuria is one of the diabetes symptoms which means urine excretion is
more than usual. High amounts of solutes within the renal tubules cause a
passive osmotic diuresis and increased urine volume. In Diabetic patients,
high urinary glucose levels exceed tubular reabsorption capacity, leading to
increased glucose levels in the renal tubules; water follows passively,
resulting in glucosuria and increased urine volume.
Pathophysiology of Polydipsia
Polydipsia can be the primary indication that blood glucose levels may be
high. In diabetic patients, a high blood glucose level causes the kidney to
produce more urine to remove excess glucose from the body. Moreover,
intracellular dehydration occurs due to high blood glucose levels, and the
hypothalamus activation sends the signal for thirst (Christ-Crain et al., 2019,
pp. 2-3). The brain tells the body to increase the amount of fluid ingested
because more urine is being produced to decrease the glucose circulating in
the bloodstream. Seladi-Schulman (2020) states that Persistent feelings of
thirst can also be caused by dehydration, osmotic diuresis, an increase in
urination due to excess glucose entering the kidney tubules which can’t be
reabsorbed, leading to increased water in the tubules, and mental health
issues, such as psychogenic polydipsia.
Pathophysiology of Polyphagia
Polyphagia is an excessive hunger feeling. This hunger usually dissipates
once the person satisfies the craving by eating. In diabetics, the sense of
hunger does not dissipate following consuming food. in diabetes, glucose
can’t enter cells to be used for energy due to either low insulin levels or
insulin resistance. The issue occurs when the conversion from glucose to
energy is impaired, leading to continued hunger. With this being said, when
the person consumes food, the glucose from that food then leads to increased
blood glucose levels.
(polyuria) Hyperglycemia acts as an osmotic diuretic. The amount of
glucose filtered by the glomeruli of the kidneys exceeds the amount
that can be reabsorbed by the renal tubules. Glycosuria results
accompanied by large amounts of water lost in the urine. (polydipsia)
Because elevated blood glucose levels, water is osmotically attracted
from body cells which results in intracellular dehydration and
hypothalamic stimulation of thirst. (polyphagia) Depletion of cellular
stores of carbohydrates, fats, and proteins results in cellular starvation
and a corresponding increase in hunger.