Signs and symptoms
Symptoms of high blood sugar including increased thirst (polydipsia), increased volume of urination (polyuria), and increased hunger (polyphagia).Symptoms of HHS include:

Altered level of consciousness
Neurologic signs including: blurred vision, headaches, focal seizures, myoclonic jerking, reversible paralysis
Motor abnormalities including flaccidity, depressed reflexes, tremors or fasciculations
Hyperviscosity and increased risk of blood clot formation
Dehydration
Weight loss
Nausea, vomiting, and abdominal pain
Weakness
Low blood pressure with standing

Cause
The main risk factor is a history of diabetes mellitus type 2. Occasionally it may occur in those without a prior history of diabetes or those with diabetes mellitus type 1. Triggers include infections, stroke, trauma, certain medications, and heart attacks.Other risk factors:

Lack of sufficient insulin (but enough to prevent ketosis)
Poor kidney function
Poor fluid intake (dehydration)
Older age (50–70 years)
Certain medical conditions (cerebral vascular injury, myocardial infarction, sepsis)
Certain medications (glucocorticoids, beta-blockers, thiazide diuretics, calcium channel blockers, and phenytoin)

Pathophysiology
HHS is usually precipitated by an infection, myocardial infarction, stroke or another acute illness. A relative insulin deficiency leads to a serum glucose that is usually higher than 33 mmol/L (600 mg/dL), and a resulting serum osmolarity that is greater than 320 mOsm. This leads to excessive urination (more specifically an osmotic diuresis), which, in turn, leads to volume depletion and hemoconcentration that causes a further increase in blood glucose level. Ketosis is absent because the presence of some insulin inhibits hormone-sensitive lipase-mediated fat tissue breakdown.
In those with more significant symptoms birth control pills or the diuretic spironolactone may be useful.Up to 80% of women report having some symptoms after ovulation and before the beginning of menstruation, but these symptoms generally do not cause substantial disruption. These symptoms qualify as PMS in approximately 20 to 30% of pre-menopausal women. Premenstrual dysphoric disorder (PMDD) is a more severe form of PMS that has greater psychological symptoms. PMDD affects 3 to 8% of pre-menopausal individuals. Antidepressant medication of the selective serotonin reuptake inhibitors class may be used for PMDD in addition to the usual measures for PMS. Signs and symptoms
More than 200 different symptoms have been associated with PMS. Common emotional and non-specific symptoms include stress, anxiety, difficulty with sleep, headache, feeling tired, mood swings, increased emotional sensitivity, and changes in interest in sex. Problems with concentration and memory may occur. There may also be depression or anxiety.Physical symptoms associated with the menstrual cycle – but not necessarily with PMS, which is symptoms that appear before menstruation, rather than during menstruation – include bloating, lower back pain, cramps in the pelvic area, constipation/diarrhea, swelling or tenderness in the breasts, cyclic acne (acne that appears and disappears at predictable times during the menstrual cycle), joint or muscle pain, and food cravings. The exact symptoms and their intensity vary significantly from person to person, and even somewhat from cycle to cycle and over time.