酮体

血液或尿液中的酮体表明您的身体正在燃烧脂肪而非葡萄糖作为能量来源。酮体的存在意味着您的身体正在使用备用能量源——脂肪。如果您患有1型糖尿病，高浓度的酮体可能是危险的。酮体水平过高可能导致一种潜在致命并发症，称为糖尿病相关酮症酸中毒（DKA）。

什么是酮体？

酮体（或称酮体群）是您身体在使用脂肪而非葡萄糖获取能量时产生的酸。您的身体主要通过饮食中的碳水化合物获取能量，转化为葡萄糖。如果从葡萄糖中获取的能量不足，身体就会分解脂肪以获取能量，从而释放出酮体，这些酮体通过血液循环输送，给身体的组织提供能量，最后通过尿液排出。

在血液中有少量酮体是正常（且安全）的，因为当可用的葡萄糖不足时，身体使用备用能量源——脂肪是正常的。

然而，过多的酮体会使您的血液变得酸性和有毒，这被称为酮症酸中毒。如果您患有糖尿病，过多的酮体可能会导致糖尿病相关酮症酸中毒（DKA）。未经治疗，DKA是威胁生命的，因此及时治疗至关重要。

酮体在体内的作用是什么？

酮体在没有葡萄糖的情况下为您的大脑和身体提供能量，葡萄糖是您身体的主要能量来源。可以将酮体视为在主要能源耗尽、低或不可用时的备用能量储备。

通常情况下，您的身体会将食物分解成葡萄糖。胰岛素是一种激素，可以帮助您的细胞利用葡萄糖作为能量源或储存起来，以备后用。

如果您摄入的碳水化合物不足，您的身体便会进入酮症状态。在此状态下，您的身体会分解脂肪以获取能量，同时释放出酮体。酮体为细胞和组织提供能量，使身体继续工作。酮症是一种正常的生理过程。例如，您的身体在以下情况下可能会进入酮症（并产生更多的酮体）：

睡觉时。
禁食时。
锻炼时。
进行生酮饮食时。

进行生酮饮食的人故意减少碳水化合物的摄入，增加脂肪类食物，以使他们的身体燃烧更多的脂肪。根据您的健康状况，通过生酮饮食诱导酮症可能会带来好处。但在尝试这种饮食之前，您始终应咨询医疗保健提供者。这种饮食会对您的身体造成重大改变，并不适合所有人。此外，生酮饮食非常限制，长时间坚持可能很困难。

酮体的来源是什么？

酮症发生在您的肝脏中。肝脏将酮体释放到血液中，酮体在全身流动，为身体提供能量。一旦完成工作，它们就会通过尿液排出体外。

与酮体相关的常见疾病和病症是什么？

了解酮体的作用并监测酮体水平对于糖尿病患者尤其重要，特别是1型糖尿病患者。1型糖尿病是一种使您的身体无法生产胰岛素的疾病。胰岛素是帮助您的身体利用葡萄糖作为能量来源的激素。

胰岛素的问题会导致血糖水平升高（高血糖），并可能导致血液中出现过多的酮体。这可能引发糖尿病相关酮症酸中毒（DKA）。DKA在1型糖尿病患者中更为常见，但2型糖尿病患者也可能发生。

酒精使用障碍患者有可能面临酒精性酮症酸中毒的风险。长期酗酒的人可能会发展出危险的高酮体水平。这通常发生在酗酒后呕吐，导致营养摄入不足。与DKA类似，酒精相关的酮症酸中毒是一种医疗紧急情况，需要立即治疗。

高酮体的症状有哪些？

如果您患有糖尿病并出现高酮体的症状，请立即联系您的医疗提供者或前往急诊室。

早期症状与高血糖的症状相似，包括：

需要比平常更频繁地排尿。
感到极度口渴。
口干和脱水。
皮肤干燥。
头痛。

如果不进行治疗，DKA可能会迅速发展（在24小时内或更短时间内）。症状包括：

恶心与呕吐。
疲劳（即使休息也感到疲倦和虚弱）。
腹痛。
呼吸急促。
意识混乱。
带有水果气味的呼吸（有时被称为“酮味”）。

Ketones

Ketones in your blood or urine indicate that your body is burning fats instead of glucose for energy. Having ketones means your body is using its backup energy source — fats. If you have Type 1 diabetes, high ketones can be dangerous. Levels that are too high can put you at risk of a potentially fatal complication called diabetes-related ketoacidosis (DKA).

What are ketones?

Ketones, or ketone bodies, are acids your body makes when it’s using fat instead of glucose for energy. Your body gets most of its energy from glucose, a sugar that mainly comes from carbohydrates in your diet. If you don’t get enough energy from glucose, your body breaks down fats for energy instead. The breakdown releases ketones that travel through your bloodstream. The ketones fuel your body’s tissues and eventually exit in your urine (pee).

It’s normal (and safe) to have some ketones in your blood because it’s normal for your body to use its backup energy source — fats — when there’s not enough usable glucose.

But too many ketones can make your blood acidic and toxic. This is called ketoacidosis. If you have diabetes, too many ketones can cause diabetes-related ketoacidosis (DKA). DKA is life-threatening without treatment. It’s crucial to get treated right away.

What do ketones do in your body?

Ketones fuel your brain and body in the absence of glucose, your body’s primary energy source. Think of ketones as your backup energy reserve when the main source is depleted, low or unusable.

Typically, your body breaks down food into glucose. A hormone called insulin helps your cells use glucose as an energy source or store it for when you need it later.

Your body will switch to ketosis if you’re not getting enough carbohydrates. During ketosis, your body breaks down fats for energy, releasing ketones. The ketones energize cells and tissue so your body can keep working. Ketosis is a normal process. For example, your body can go into ketosis (and make more ketones) when:

You’re asleep.
You’re fasting.
You’re exercising.
You’re on the keto diet.

People on the keto diet purposely cut back on carbs and eat more fatty foods so their bodies will burn more fat. Inducing ketosis with the keto diet may provide benefits depending on your health. But you should always speak with a healthcare provider before trying this diet. It causes major changes to your body and isn’t for everyone. Also, the keto diet is very restrictive, so it can be difficult to stick to for extended periods of time.

Where are ketones located?

Ketosis occurs in your liver. Your liver releases the ketones into your bloodstream, where they travel throughout your body, providing energy. Once they’ve done their job, you pee them out.

What are the common conditions and disorders associated with ketones?

Understanding what ketones do and keeping track of ketone levels is especially important if you have diabetes — Type 1 diabetes, in particular. Type 1 diabetes is a condition that prevents your body from making insulin. Insulin is the hormone that helps your body use glucose for energy.

Problems with insulin cause your blood sugar levels to rise (hyperglycemia) and can cause too many ketones to build up in your blood. This can lead to diabetes-related ketoacidosis (DKA). DKA is more common in people with Type 1 diabetes but can happen with Type 2 diabetes, too.

People with alcohol use disorder are at risk of alcoholic ketoacidosis. People with a history of heavy drinking may develop dangerously high levels of ketones. This usually happens after binge drinking and vomiting, which prevents you from getting enough nutrition. Like DKA, alcohol-related ketoacidosis is a medical emergency that requires immediate treatment.