Why Do I Feel Weird After Drinking Milk Tea?

November 18, 2025 •

4 min read

According to a study published in the journal Advances in Nutrition, the caffeine in tea can significantly disrupt the body's natural processes, leading to discomfort. If you've ever asked, "why do I feel weird after drinking milk tea?", you're not alone. This unsettling sensation can stem from various factors, from caffeine sensitivity to digestive issues caused by milk or tannins.

Quick Summary

Several factors, including caffeine overload, lactose intolerance, and the effects of tannins, can cause feelings of discomfort or anxiety after consuming milk tea. Understanding these triggers and making simple adjustments can help you enjoy this popular beverage without negative side effects.

Key Points

Caffeine Sensitivity: High caffeine content can lead to anxiety, restlessness, and sleep disruption, especially for sensitive individuals or with overconsumption.
Lactose Intolerance: Difficulty digesting lactose in milk can cause bloating, cramps, and nausea, making you feel uncomfortable.
Tannin Effects: Astringent tannins in tea can irritate the stomach lining, especially when consumed on an empty stomach, causing nausea.
Sugar Crash: High sugar content can cause rapid blood sugar spikes and crashes, leading to fatigue, irritability, and lightheadedness.
Additive Reactions: Certain additives, like tapioca pearls or artificial ingredients, can trigger digestive upset in some people.
Mindful Consumption: Drinking with food, choosing low-caffeine options, and reducing sugar intake can help prevent adverse reactions.
Moderation is Key: Regular or excessive intake, particularly of high-sugar versions, can lead to more significant health problems over time.

The Unsettling Truth Behind Your Milk Tea

For many, milk tea is a beloved comfort drink. Yet, for some, it triggers a cascade of unpleasant symptoms, ranging from a jittery feeling to stomach cramps. The key to understanding this reaction lies in dissecting the primary ingredients: tea, milk, and sugar, and how they interact with your body's unique physiology.

Caffeine Overload and Anxiety

Tea leaves, particularly black tea, contain significant amounts of caffeine. While this can provide a pleasant energy boost for some, others are highly sensitive to its effects. A higher-than-usual dose of caffeine, especially if you have a low tolerance or consume it rapidly, can lead to a state of overstimulation. This triggers the body's 'fight or flight' response, increasing heart rate and blood pressure, which can mimic or exacerbate feelings of anxiety. This jitteriness and heightened alertness can easily be described as feeling 'weird.' In some cases, excess caffeine can also disrupt sleep patterns, causing fatigue and irritability later.

Digestive Distress from Lactose and Tannins

Digestive issues are another common culprit behind the strange sensation. This can be caused by two main components:

Lactose Intolerance: Many people, particularly those of Asian descent, have some degree of lactose intolerance, meaning their bodies don't produce enough lactase—the enzyme needed to digest lactose, the sugar in milk. Consuming milk tea can then lead to symptoms such as bloating, gas, stomach cramps, and nausea, which collectively create a feeling of unease and discomfort.
Tannins: Tea leaves contain natural compounds called tannins, which give tea its characteristic astringent flavor. When consumed on an empty stomach, tannins can irritate the stomach lining, leading to nausea or general upset. Milk is often added to tea precisely because its proteins bind with tannins, reducing this effect, but for some sensitive individuals, it's not enough to prevent discomfort.

Blood Sugar Swings and the Crash

Many popular milk tea varieties are loaded with sugar. While this provides a quick burst of energy, it causes a rapid spike in blood sugar followed by an equally quick crash. This 'sugar crash' can leave you feeling fatigued, irritable, and lightheaded, a sensation that is often interpreted as feeling 'weird.' For those with or at risk of blood sugar imbalances, this rollercoaster effect is particularly pronounced.

The Impact of Additives and Preparation

Beyond the core ingredients, the preparation and additives in milk tea can also contribute to unwanted side effects. Bubble tea, for instance, often contains tapioca pearls, which can be hard to digest for some. Artificial sweeteners, flavorings, and thickeners used in commercial preparations can also cause adverse reactions in sensitive individuals, leading to various forms of discomfort.

Potential Causes of Feeling Weird After Milk Tea


Cause	Contributing Factor	Common Symptoms	Who is Most Affected?
Caffeine Sensitivity	High caffeine content in black tea varieties.	Jitteriness, anxiety, increased heart rate, restlessness, sleep disruption.	Individuals with high caffeine sensitivity, those who drink it quickly, or late in the day.
Lactose Intolerance	Inability to properly digest lactose, the sugar in milk.	Bloating, gas, cramping, nausea, abdominal pain.	Many adults, especially of Asian, African, or Hispanic descent.
Tannin Irritation	Astringent compounds in tea leaves that can irritate the stomach lining.	Nausea, stomach discomfort, upset stomach.	Individuals who drink tea on an empty stomach or consume over-brewed tea.
Sugar Crash	Rapid spike and subsequent drop in blood sugar levels from excessive sugar.	Fatigue, irritability, lightheadedness, headaches.	People with blood sugar sensitivities, like those with pre-diabetes or diabetes.
Additive Sensitivity	Artificial sweeteners, flavors, or thickeners used in commercial milk tea.	Varied, can include digestive upset, headaches, or allergic reactions.	Those with sensitivities to specific food additives.

How to Prevent Feeling Weird After Milk Tea

By identifying the potential cause of your discomfort, you can take steps to mitigate or avoid it altogether. Simple modifications can make all the difference.

Switch to a Low-Caffeine or Herbal Tea Base: If caffeine is the issue, opt for a tea with lower caffeine content, such as green or white tea, or choose a naturally caffeine-free herbal tea like rooibos.
Use Lactose-Free Alternatives: For those with lactose intolerance, swapping dairy milk for a lactose-free or plant-based alternative like oat milk, almond milk, or soy milk can eliminate digestive symptoms.
Drink with Food: Avoid drinking milk tea on an empty stomach. Enjoy it with a meal or snack to help buffer the effects of tannins and slow down sugar absorption.
Control Sugar Content: Order your milk tea with less sugar or no sugar at all. This prevents blood sugar spikes and the subsequent crash.
Pay Attention to Your Body: Keep a journal of what you drink and how you feel afterward. This can help you identify specific ingredients or brands that trigger your symptoms.

Conclusion

Feeling weird after drinking milk tea is a common experience with several possible causes. Whether it's the stimulant effects of caffeine, the digestive repercussions of lactose intolerance and tannins, or the rapid fluctuations in blood sugar, pinpointing the specific trigger is the first step towards a solution. By making mindful choices about your tea's ingredients and preparation, you can continue to enjoy this comforting beverage without the unwanted side effects. If symptoms persist or are severe, consulting a healthcare professional is always the best course of action.

A Note on Severity

While most reactions to milk tea are mild, some individuals may have more severe sensitivities. A true allergy to tea is rare but possible, so always be aware of your body's signals. For persistent or severe symptoms, medical advice is crucial.

A Balanced Approach to Enjoyment

Remember that moderation is key. Indulging in milk tea occasionally is one thing, but making it a daily habit, especially if it's high in sugar and fat, can lead to other health issues over time. Balance your enjoyment of milk tea with a varied, nutritious diet and stay well-hydrated throughout the day.

Mayo Clinic's Guide to Lactose Intolerance

Frequently Asked Questions

Yes, for some people, the high caffeine content in milk tea can cause or worsen feelings of anxiety and restlessness by stimulating the central nervous system and triggering a 'fight or flight' response. It can also amplify existing anxiety symptoms and, in high doses, has been linked to panic attacks in susceptible individuals.

Nausea can be caused by the tannins in tea, especially when consumed on an empty stomach, or by lactose intolerance if you have difficulty digesting the milk. You can try drinking milk tea with food or switching to a lactose-free or herbal tea alternative to alleviate this.

This sensation is often linked to a sugar crash. The high sugar content can cause a quick spike in blood glucose, followed by a rapid drop that can lead to dizziness, fatigue, and irritability. It can also be related to dehydration, as caffeine is a diuretic.

Yes, digestive problems like bloating, gas, and cramps are common side effects, especially for people with lactose intolerance. The inability to properly digest the lactose in milk can lead to significant gastrointestinal discomfort.

Yes, you can make several adjustments to mitigate the side effects. Consider using a lactose-free or plant-based milk, reducing or eliminating sugar, choosing a low-caffeine tea base, and avoiding drinking it on an empty stomach.

Tannins are astringent compounds in tea that can irritate the stomach lining, potentially causing nausea or a feeling of unease. Adding milk can help by binding with the tannins, but brewing for less time can also reduce their concentration.

A true allergy to tea is very rare, though sensitivities are common. While typical 'weird' feelings are likely from caffeine, sugar, or lactose, severe symptoms like hives, swelling, or difficulty breathing could indicate a serious allergy and require immediate medical attention.