A 41-yr-old woman presented 3 h after ingesting approximately 50 g of caffeine. [ncbi.nlm.nih.gov]

• Constipation

  Some symptoms of caffeine withdrawal include headaches, irritability, nervousness, nausea, constipation and muscular tension. [uhs.umich.edu]

  Though more research is needed, studies have indicated that caffeine could both precipitate and alleviate headache, boost athletic performance and memory, protect against type 2 diabetes, prevent constipation, and exacerbate menopausal hot flashes. 4. [consumerreports.org]

  May Be Useful In Treatment Of: ALIMENTARY CANAL: Cancer, Constipation, Indigestion (dyspepsia), Ulcer (duodenal and peptic). [web.archive.org]

  Many patients with nOH also have autonomic failure resulting in constipation and anhidrosis, so these side effects may be salutary for some patients. [doi.org]

• Tachycardia

  Atrial tachycardia time from a Holter recording was 44.2 minute/day before the caffeine load, compared with 215.2 minute/day during the caffeine load. [ncbi.nlm.nih.gov]

• Palpitations

  It used to be believed that premature cardiac contractions, which usually cause no symptoms or mild symptoms such as heart palpitations, ‘skipped’ beats or fluttering, were harmless. [nbcnews.com]

  "If it's red-colored and it's sweet, kids might take three, four or five of them and go into an anxiety attack and palpitations," he said. "Kids get anxious when they take caffeine and it could put them over the top." [abcnews.go.com]

  Heart Palpitations Caffeine stimulates the central nervous system. It speeds up the heart rate and can cause the heart to flutter or palpitate. Energy drinks: health risks and toxicity 8. [inc.com]

  Of these energy drink users, 29 percent reported "weekly jolt and crash episodes," and 19 percent reported heart palpitations from drinking energy drinks. [sciencedaily.com]

  Short-Term Effects of Caffeine Raised blood pressure Trouble sleeping (insomnia) Frequent urination Long-Term Caffeine Health Risks Heart palpitations or other heart problems Mental health changes On the other hand, Brown says some evidence suggests caffeine [unitypoint.org]

• Irregular Heart Rhythm

  heart rhythms Have high blood pressure Take certain medicines or supplements, including stimulants, certain antibiotics, asthma medicines, and heart medicines. [nlm.nih.gov]

  The report challenges a widely held belief that caffeinated drinks cause irregular heart rhythms that can lead to heart failure or dangerous heart rhythm disorders and is another vindication for coffee as a safe drink. [nbcnews.com]

• Orthostatic Hypotension

  Neurogenic orthostatic hypotension. N Engl J Med 358(6):615–624 CrossRef PubMed Google Scholar 7. Low PA, Singer W (2008) Management of neurogenic orthostatic hypotension: an update. [doi.org]

• Halitosis

  Foosh energy mints have 5,555 mg of caffeine per 100g - that’s 139 cups of coffee (and, we assume, without the halitosis). Buzz Bites Chocolate Chews were the second highest on the adult sweeties list with 1,639mg of caffeine per 100g. [theguardian.com]

• Bruxism

  Marcin Berger, Monika Litko, Michał Ginszt, Hassan Alharby, Jacek Szkutnik, Piotr Majcher and Jolanta Szymańska, Use of common stimulants and awake bruxism – a survey study, Polish Journal of Public Health, 126, 3, (2016). [dx.doi.org]

• Xerostomia

  Morita, Relationship between xerostomia and gingival condition in young adults, Journal of Periodontal Research, 50, 1, (74-79), (2014). Matthew A. Tucker, Matthew S. Ganio, J. D. Adams, Lemuel A. Brown, Christian B. Ridings, Jenna M. [doi.org]

• Muscle Twitch

  twitching, rambling flow of thought and speech, tachycardia or cardiac arrhythmia, periods of inexhaustibility or psychomotor agitation (unintentional motion, say, rapidly bouncing one leg). [newsfeed.time.com]

  Muscle Twitches and Spasms A high volume or prolonged use of caffeine in the body can cause the muscles to cramp or move erratically. Energy drinks: health risks and toxicity 6. [inc.com]

  twitching, rambling flow of thought and speech, tachycardia or cardiac arrhythmia, periods of inexhaustibility, or psychomotor agitation. [draxe.com]

  Symptoms of overdose may include agitation; anxiety; confusion; frequent urination; irregular or fast heartbeat; muscle twitching; ringing in the ears; seizures; stomach pain; trouble sleeping. [drugs.com]

  It can also cause flushed face, increased urination, muscle twitching and agitation. Some people feel these effects even with a very small amount (in some people as little as 250 mg, or two cups of coffee a day). [camh.ca]

• Muscle Cramp

  More toxic effects such as nausea, vomiting, muscle cramps, twitching and agitation may occur when a child consumes more than 4.5 mg of caffeine per pound of body weight. [dailymail.co.uk]

• Sweating

  Toxic manifestations included hypertonia, sweating, tachycardia, cardiac failure, pulmonary oedema and metabolic disturbances (metabolic acidosis, hyperglycaemia and creatine kinase elevation). [ncbi.nlm.nih.gov]

  Too much caffeine may also lead to anxiety-related feelings such as excessive nervousness, sweating and tremors. [uhs.umich.edu]

  It's sweat-proof and hypo-allergenic. But it's what's on the inside that counts. The user attaches an adhesive patch made with guarana extract, which has twice the caffeine concentration as coffee beans. [techinsider.io]

  Side effects of caffeine consumption include thirst, anxiety, insomnia, irritability, blurry vision, dry mouth, clamminess, sweat production, increased blood sugar and urination, respiratory distress, rapid heartbeats and diarrhea. [livestrong.com]

  These symptoms can include: headache fatigue (tiredness, lethargy) drowsiness (sleepiness, yawning) nausea depression difficulty concentrating inability to think clearly irritability anxiety sweating muscle pains and weakness. [positivechoices.org.au]

• Flushing

  If you’ve had more than 250 mg of caffeine (two to three cups of brewed coffee) and experienced five or more of the following symptoms, says the guide, you’ve probably been caffeine-buzzed: restlessness, nervousness, excitement, insomnia, flushed face [newsfeed.time.com]

  But hours later, he was flushed, lost his equilibrium and became nauseated. "He lay down on the couch, not asleep, but acting comatose and that night it really kicked in and he needed a bucket by the side of his bed," his wife said. [abcnews.go.com]

  Water also naturally flushes caffeine from your body and keeps you hydrated. If you are a coffee drinker, gradually switch from regular coffee to decaf. [my.clevelandclinic.org]

  It can also cause flushed face, increased urination, muscle twitching and agitation. Some people feel these effects even with a very small amount (in some people as little as 250 mg, or two cups of coffee a day). [camh.ca]

  […] alertness that caffeine gives them, unpleasant symptoms experienced by many consumers, especially those who are addicted, include: Restlessness Nervousness Excitement Difficulty sleeping Agitation Muscle twitching Rambling flow of thoughts and speech Flushed [verywellmind.com]

• Anxiety Disorder

  Caffeine toxicity remains a rarely reported condition, which may mimic anxiety disorders. Anxiety disorder patients do not consume toxic amounts of caffeine. [ncbi.nlm.nih.gov]

  CrossRef Google Scholar × Volume 19, Issue 1 February 1989, pp. 211-214 Synopsis Caffeine toxicity remains a rarely reported condition, which may mimic anxiety disorders. Anxiety disorder patients do not consume toxic amounts of caffeine. [doi.org]

• Euphoria

  When taken in low to moderate doses, positive caffeine effects can include alertness, mild euphoria and better cognitive performance (e.g. concentration, problem solving). [sleephealthfoundation.org.au]

  Many of caffeine’s effects, including fat burning, strength benefits, and euphoria, are subject to tolerance, and may not occur in people used to caffeine, no matter how large the dose is. [examine.com]

  “Whereas low-dose caffeine effects are wakefulness, a little bit of arousal, and slight euphoria,” Fredholm says, “high-dose effects are anxiety, irritation, and general mental discomfort—a completely different kettle of fish.” [cen.acs.org]

• Auditory Hallucination

  An elderly patient with a history of chronic migraine was hospitalized with systolic hypertension and significant mental status changes, including increasing confusion, combative behavior, and remarkably detailed auditory hallucinations of several weeks [ncbi.nlm.nih.gov]

• Urinary Incontinence

  Lee, Green tea drinking is inversely associated with urinary incontinence in middle‐aged and older women, Neurourology and Urodynamics, 30, 7, (1262-1265), (2011). C. [doi.org]

  Nevertheless, individuals with various conditions such as generalized anxiety disorder, panic disorder, primary insomnia, gastroesophageal reflux, pregnancy and urinary incontinence are often advised to reduce or eliminate regular caffeine use. [web.archive.org]

  If you have urinary incontinence, you may experience a greater "urgency" to urinate after consuming a caffeinated beverage. You will need to monitor your reaction and tolerance to caffeine to determine how you are affected. [medicinenet.com]

• Urinary Urgency

  This may be due to voluntary restriction of intake for self-management of common conditions causing urinary urgency and urinary frequency including benign prostatic hyperplasia (BPH), overactive bladder, neurogenic bladder, stress incontinence or similar [doi.org]

• Nocturia

  Supine hypertension commonly leads to a pressure diuresis that occurs resulting in nocturia and blood volume depletion overnight. This nocturnal forced diuresis can be decreased by elevating the head of the bed. [doi.org]

• Headache

  Abstract Caffeinated headache medications, either alone or in combination with other treatments, are widely used by patients with headache. [ncbi.nlm.nih.gov]

  In experimental studies, 50 percent of people experienced headache and 13 percent had clinically significant distress or functional impairment -- for example, severe headache and other symptoms incompatible with working. [hopkinsmedicine.org]

  Caffeine and rebound headache (medication overuse headache) Rebound headache is a condition that develops from the overuse or misuse of any headache medicine, including those that have caffeine. Medicines that contain caffeine can be beneficial. [my.clevelandclinic.org]

• Insomnia

  Caffeine intake and insomnia levels were measured using the Modified Caffeine Consumption Questionnaire and the Pittsburgh Insomnia Rating Scale (PIRS) in 130 clinically stable participants who were living with HIV, taking antiretroviral therapy, and [ncbi.nlm.nih.gov]

  Some examples of the side effects of excessive caffeine intake include difficulty concentrating, insomnia, muscle tremors, fast heartbeat, jitteriness, heartburn, nervousness, stomach upset and irritability. [news-medical.net]

  If you do eat or drink too much caffeine, it can cause health problems, such as Restlessness and shakiness Insomnia Headaches Dizziness Rapid or abnormal heart rhythm Dehydration Anxiety Dependency, so you need to take more of it to get the same results [nlm.nih.gov]

  Caffeine warning signs You may want to cut back on caffeine if you experience side effects such as: Headache Insomnia Nervousness Irritability Restlessness Stomach upset Fast heartbeat Muscle tremors [bbc.com]

• Tremor

  On the other hand, high doses can cause noticeable signs of mental confusion and error induction in intellectual tasks, anxiety, restlessness, muscle tremors, tachycardia, labyrinthine changes, and tinnitus. [ncbi.nlm.nih.gov]

  Call an ambulance straight away by dialling triple zero (000) if you experience any of the following effects. tremors nausea and vomiting very fast and irregular heart rate confusion and panic attack seizures.5 It’s possible to die from having too much [adf.org.au]

  Caffeine warning signs You may want to cut back on caffeine if you experience side effects such as: Headache Insomnia Nervousness Irritability Restlessness Stomach upset Fast heartbeat Muscle tremors [bbc.com]

• Seizure

  Further research is required to elucidate the effect of these variables on seizure duration. [ncbi.nlm.nih.gov]

• Agitation

  The patient exhibited agitations, irritability, tachycardia, tachypnoea, diuresis, electrolyte abnormalities, hyperglycaemia and metabolic acidosis, for which he received supportive treatment. No seizure activity was observed. [ncbi.nlm.nih.gov]

Many combinations of caffeine concentration and duration produced comparable results; however, treatment with 3 g∙L−1 for 24 h was the most effective caffeine treatment on the basis of the number of seeds recovered, as well as the size and incidence of [ncbi.nlm.nih.gov]

Many combinations of caffeine concentration and duration produced comparable results; however, treatment with 3 g∙L −1 for 24 h was the most effective caffeine treatment on the basis of the number of seeds recovered, as well as the size and incidence [doi.org]

DSRCT remains an aggressive malignancy, with a poor prognosis despite multi-modality treatments. In the published literature, there has been no patient who lived for three years or more without surgical excision. [ncbi.nlm.nih.gov]

Outcome at 5 years of age of children 23 to 27 weeks’ gestation: refining the prognosis. Pediatrics 2001;108:134–141. [doi.org]

This pattern was present for both Alzheimer’s disease–related dementia and cerebrovascular disease etiologies, and persisted in analyses restricted to nonsmokers. [ajrccm.atsjournals.org]

The role of hormone use in PD etiology and its potential influence on the caffeine-PD relation should be further explored with larger sample sizes in the future. [doi.org]

Epidemiology 7, 250 – 255. 42. Fenster, L, Hubbard, AE, Swan, SH et al. ( 1997 ) Caffeinated beverages, decaffeinated coffee, and spontaneous abortion. Epidemiology 8, 515 – 523. 43. [doi.org]

Bracken Professor and Head Chronic Disease Epidemiology Department Yale University School of Medicine Marilyn E. [web.archive.org]

Several epidemiological studies on this issue have been published since then, warranting an update of the insights on this topic. [ncbi.nlm.nih.gov]

Google Scholar | Crossref | Medline | ISI Morelli, M, Carta, AR, Kachroo, A. ( 2010 ) Pathophysiological roles for purines: Adenosine, caffeine and urate. Progress in Brain Research 183: 183 – 208. [doi.org]

McDermott, Neuroimaging with magnetoencephalography: A dynamic view of brain pathophysiology, Translational Research, 10.1016/j.trsl.2016.01.007, 175, (17-36), (2016). Mohsin H.K. Roshan, Amos Tambo and Nikolai P. [dx.doi.org]

The mechanism of action of caffeine on prevention of apnea and activation of breathing seems to be through central inhibition of adenosine receptors. [ncbi.nlm.nih.gov]

Community Preventive Services Task Force. The Guide to Community Preventive Services. Excessive Alcohol Consumption website. https://www.thecommunityguide.org/topic/excessive-alcohol-consumptionExternalexternal icon. Accessed February 4, 2020. [cdc.gov]