Water & hydration

Sources

Every numbered claim on the overview and article pages is listed here with the exact passage it rests on. 61 passages were checked word-for-word against the saved copies listed below.

Pharmacist review pending61 verified passagesUpdated 2026-10-22

Current evidence

1

Drinking water prevents dehydration, which can cause unclear thinking, mood change, overheating, constipation and kidney stones.

“Drinking water can prevent dehydration, which may cause unclear thinking, mood change, overheating, constipation, and kidney stones.”

U.S. Centers for Disease Control and Prevention — About Water and Healthier DrinksPassage verified word-for-word in saved copy
2

Water helps keep a normal temperature, cushions joints and removes waste.

“Keep a normal temperature.”
“Lubricate and cushion joints.”
“Get rid of waste through urination, perspiration, and bowel movements.”

U.S. Centers for Disease Control and Prevention — About Water and Healthier DrinksPassage verified word-for-word in saved copy
3

Adults need about 2.7 to 3.7 liters of water a day in total, from food and drinks; there is no specific amount you must drink.

“The Dietary Reference Intake for water is between 91 and 125 fluid ounces (2.7 to 3.7 liters) of water per day for adults.”
“Keep in mind that this is the total amount you get from both food and beverages every day. There is no specific recommendation for how much water you should drink.”

MedlinePlus (U.S. National Library of Medicine) — Water in dietPassage verified word-for-word in saved copy
4

Drinking when thirsty and with meals is usually enough to stay hydrated.

“If you drink fluids when you feel thirsty and have beverages with meals, you should get enough water to keep you hydrated.”

MedlinePlus (U.S. National Library of Medicine) — Water in dietPassage verified word-for-word in saved copy
5

Thirst may change with age, so it matters to drink through the day.

“As you get older, your thirst may change. It is always important to take in fluids throughout the day.”

MedlinePlus (U.S. National Library of Medicine) — Water in dietPassage verified word-for-word in saved copy
6

Alcohol does not hydrate; it makes the body release water.

“Alcohol does not add to the body's water because it is a diuretic. It causes the body to release water.”

MedlinePlus (U.S. National Library of Medicine) — Water in dietPassage verified word-for-word in saved copy
7

Water has no calories, so swapping sugary drinks for water can cut calories.

“Water has no calories, so replacing sugary drinks with plain water can help reduce caloric intake.”

U.S. Centers for Disease Control and Prevention — About Water and Healthier DrinksPassage verified word-for-word in saved copy
8

Up to 400 mg of caffeine a day, about 2 to 3 cups of plain coffee, can be part of a healthy diet for most adults.

“Moderate caffeine consumption (up to 400 mg per day) can be a part of a healthy diet for most adults. That's about 2 to 3 cups of plain coffee.”

U.S. Centers for Disease Control and Prevention — About Water and Healthier DrinksPassage verified word-for-word in saved copy
9

Some older adults lose their sense of thirst and do not drink enough.

“Some people lose their sense of thirst as they age, so they don't drink enough fluids.”

MedlinePlus (U.S. National Library of Medicine) — Dehydration (health topic)Passage verified word-for-word in saved copy
10

Mild dehydration shows as thirst, a dry mouth, passing little urine and darker yellow urine.

“Thirst”
“Dry or sticky mouth”
“Not urinating much”
“Darker yellow urine”

MedlinePlus (U.S. National Library of Medicine) — DehydrationPassage verified word-for-word in saved copy
11

Severe dehydration, with confusion or a rapid heartbeat, is a life-threatening emergency.

“Severe dehydration is a life-threatening emergency.”
“Irritability or confusion”
“Rapid heartbeat”

MedlinePlus (U.S. National Library of Medicine) — DehydrationPassage verified word-for-word in saved copy
12

For mild dehydration, sip water or suck ice cubes; do not take salt tablets.

“Try sipping water or sucking on ice cubes.”
“Do not take salt tablets. They can cause serious complications.”

MedlinePlus (U.S. National Library of Medicine) — DehydrationPassage verified word-for-word in saved copy
13

Older adults and people with conditions such as diabetes are at higher risk of dehydration.

“Older adults and people with certain diseases, such as diabetes, are also at higher risk for dehydration.”

MedlinePlus (U.S. National Library of Medicine) — DehydrationPassage verified word-for-word in saved copy
14

You need more water in hot weather, when active, and with fever, diarrhea or vomiting.

“Your body needs more water when you are:”
“In hot climates.”
“More physically active.”
“Running a fever.”
“Having diarrhea or vomiting.”

U.S. Centers for Disease Control and Prevention — About Water and Healthier DrinksPassage verified word-for-word in saved copy
15

Urine colour also changes with vitamins and medicines; blood in the urine, even once, needs a provider.

“Dark yellow or orange urine can be caused by:”
“B complex vitamins or carotene”
“Blood in your urine, even once”

MedlinePlus (U.S. National Library of Medicine) — Urine - abnormal colorPassage verified word-for-word in saved copy
16

With heart failure, limiting fluid and salt can prevent swelling and breathlessness; follow your provider's fluid advice.

“Limiting how much you drink and how much salt (sodium) you take in can help prevent these symptoms.”
“Your provider will monitor the level of sodium in your blood and may advise you to modify what fluids or how much fluid you consume.”

MedlinePlus (U.S. National Library of Medicine) — Heart failure - fluids and diureticsPassage verified word-for-word in saved copy
17

With heart failure, call your provider if weight rises more than 2 to 3 pounds in a day or 5 pounds in a week.

“Contact your provider if your weight goes up by more than 2 to 3 pounds (1 to 1.5 kilograms, kg) in a day or 5 pounds (2 kg) in a week.”

MedlinePlus (U.S. National Library of Medicine) — Heart failure - fluids and diureticsPassage verified word-for-word in saved copy
18

Low blood sodium makes brain cells swell and can be a life-threatening emergency.

“When your body's sodium level drops too much, it can be a life-threatening emergency.”
“Brain cells are especially sensitive to swelling, and this causes many of the symptoms of low blood sodium.”

MedlinePlus (U.S. National Library of Medicine) — Low blood sodiumPassage verified word-for-word in saved copy
19

During sports or vigorous activity, drinks with electrolytes help keep sodium in a healthy range.

“If you play sports or do other vigorous activity, drink fluids such as sports drinks that contain electrolytes to keep your body's sodium level in a healthy range.”

MedlinePlus (U.S. National Library of Medicine) — Low blood sodiumPassage verified word-for-word in saved copy
20

People taking lithium need the right amounts of fluid and salt, and should tell their doctor about severe diarrhea, heavy sweating or fever.

“It is important to follow a proper diet, including the right amounts of fluid and salt during your treatment.”
“tell your doctor if you have or develop severe diarrhea, excessive sweating, or fever during your treatment.”

MedlinePlus (U.S. National Library of Medicine) — LithiumPassage verified word-for-word in saved copy
21

Too little fluid on hot days, and medicines such as beta-blockers, water pills and some mental-health medicines, make heat illness more likely.

“Not drinking enough fluids when you're active on warmer or hot days”
“Certain medicines: Examples are beta-blockers, water pills or diuretics, some medicines used to treat depression, psychosis , or ADHD”

MedlinePlus (U.S. National Library of Medicine) — Heat emergenciesPassage verified word-for-word in saved copy
22

Heat stroke can cause shock, brain damage, organ failure and death.

“Heat stroke can cause shock, brain damage, organ failure, and even death.”

MedlinePlus (U.S. National Library of Medicine) — Heat emergenciesPassage verified word-for-word in saved copy
23

Muscle cramps are the first stage of heat illness.

“Muscle cramps are the first stage of heat illness.”

MedlinePlus (U.S. National Library of Medicine) — Heat emergenciesPassage verified word-for-word in saved copy
24

In hot work, drinking enough water and watching urine colour and amount help prevent heat illness.

“These include drinking enough water and monitoring the color and amount of urine output.”

CDC National Institute for Occupational Safety and Health — Heat Stress: Workplace RecommendationsPassage verified word-for-word in saved copy
25

Fruits and vegetables with high water content add to fluid intake.

“Foods, especially those with high water content such as many fruits and vegetables, can also add to fluid intake.”

U.S. Centers for Disease Control and Prevention — About Water and Healthier DrinksPassage verified word-for-word in saved copy
26

Energy drinks can contain added sugar and large amounts of caffeine and other stimulants.

“In addition to added sugar, these products may also contain large amounts of caffeine and other legal stimulants.”

U.S. Centers for Disease Control and Prevention — About Water and Healthier DrinksPassage verified word-for-word in saved copy
27

Confusion, fainting, a seizure or very high body temperature in the heat — call 911.

“Call 911 or the local emergency number if:”
“The person loses consciousness at any time.”
“There is any other change in the person's alertness (for example, confusion or seizures).”
“Fever - temperature above 104°F (40°C)”

MedlinePlus (U.S. National Library of Medicine) — Heat emergenciesPassage verified word-for-word in saved copy
28

No urine for many hours, a rapid heartbeat or extreme dizziness — these are signs of severe dehydration. Get emergency care.

“Severe dehydration is a life-threatening emergency.”
“Signs of severe dehydration include:”
“Not urinating, or very dark yellow or amber-colored urine”
“Dizziness or lightheadedness”
“Rapid heartbeat”

MedlinePlus (U.S. National Library of Medicine) — DehydrationPassage verified word-for-word in saved copy
29

Heart failure with weight up 2–3 lb in a day, or new breathlessness — call your provider.

“Contact your provider if your weight goes up by more than 2 to 3 pounds (1 to 1.5 kilograms, kg) in a day or 5 pounds (2 kg) in a week.”
“You feel short of breath when you are active or when you are at rest.”

MedlinePlus (U.S. National Library of Medicine) — Heart failure - fluids and diureticsPassage verified word-for-word in saved copy
30

Taking lithium with vomiting, diarrhea, shakiness or confusion — contact your doctor right away.

“shaking of a part of your body that you cannot control”
“diarrhea”
“vomiting”

MedlinePlus (U.S. National Library of Medicine) — LithiumPassage verified word-for-word in saved copy
31

Blood in your urine, even once — see a provider.

“See your health care provider if you have:”
“Blood in your urine, even once”

MedlinePlus (U.S. National Library of Medicine) — Urine - abnormal colorPassage verified word-for-word in saved copy

Source documents

U.S. Centers for Disease Control and Prevention — About Water and Healthier Drinks
Saved 2026-10-19 · browser page text · SHA-256 b49cdad295036dac…
MedlinePlus (U.S. National Library of Medicine) — Water in diet
Saved 2026-10-19 · download · SHA-256 53552627c84c0672…
MedlinePlus (U.S. National Library of Medicine) — Dehydration
Saved 2026-10-19 · download · SHA-256 0bf95dcc808c7c4b…
MedlinePlus (U.S. National Library of Medicine) — Dehydration (health topic)
Saved 2026-10-19 · download · SHA-256 cb444eb57cc6ffbd…
MedlinePlus (U.S. National Library of Medicine) — Heat emergencies
Saved 2026-10-19 · download · SHA-256 0bd523b7b0c067d6…
MedlinePlus (U.S. National Library of Medicine) — Urine - abnormal color
Saved 2026-10-19 · download · SHA-256 71337ce34660f47c…
MedlinePlus (U.S. National Library of Medicine) — Heart failure - fluids and diuretics
Saved 2026-10-19 · download · SHA-256 999d0b628263cf4a…
MedlinePlus (U.S. National Library of Medicine) — Low blood sodium
Saved 2026-10-19 · download · SHA-256 14f4aa22066352c9…
MedlinePlus (U.S. National Library of Medicine) — Lithium
Saved 2026-10-19 · download · SHA-256 940a4258e2affa9f…
CDC National Institute for Occupational Safety and Health — Heat Stress: Workplace Recommendations
Saved 2026-10-19 · browser page text · SHA-256 b57222f6806f47a9…

Historical perspective: Dr. Majid Ali archive

Historical perspective drawn from the authorized writings of Dr. Majid Ali, preserved in the Clarkson archive. Shown for context; it is not current medical guidance.

What to Drink on Hot Days and Everyday 2014-06-18
Source of the quoted line. His ranking of coffee and tea as 'aging-oxidant' fluids, and ginger water as a pollutant binder, are held.
Are You Dehydrated? Dr. Ali's Test 2014-05-30
Read for context. His fixed fluid targets and his claim that a self-test beats laboratory tests are held.

Claims we deliberately did not carry

His guideline of about four quarts of fluid a day for a 150 lb person, and five quarts above 170 lb.
There is no specific recommendation for how much water to drink,³ and people with heart failure may be told to limit fluid.¹⁶ Not carried.
His claim that his two-week hydration self-test is better than laboratory tests.
Not supported by the sources used here; dehydration and low blood sodium are diagnosed with an exam and blood and urine tests.¹⁸ Not carried.
His ranking of coffee and black tea as 'aging-oxidant' fluids to avoid.
Current guidance says moderate caffeine can be part of a healthy diet for most adults.⁸ Not carried.

Safety wording awaiting sign-off

The 'When to get help now' list is ProperHealth safety wording. Each line cites the official guidance it follows, and those passages are listed above with the other claims. The wording still needs pharmacist sign-off before public use.