The sensation of feeling shaky, lightheaded, or experiencing mild internal tremors is common during pregnancy. This symptom, often described as an unsettling wobbliness or mild inner vibration, arises from the body making profound physiological adjustments to support the developing fetus. While this physical unease can be startling, it is frequently a benign side effect of gestation. Understanding the root causes, which range from expected hormonal shifts to manageable lifestyle factors and, in rare cases, conditions requiring medical attention, can help reduce anxiety.
Common Physiological Causes
The body undergoes massive systemic changes during pregnancy, which often manifest as the feeling of shakiness or lightheadedness. One of the primary drivers is the change in the cardiovascular system, where blood volume increases significantly, often by 30 to 50%. Paradoxically, this increase can lead to a drop in blood pressure, known as hypotension, because hormones like progesterone cause widespread relaxation and widening of blood vessels, a process called vasodilation.
This widening means blood pools more easily in the lower extremities, especially when standing or changing positions quickly. The result is orthostatic hypotension, a temporary drop in blood pressure to the brain that causes dizziness, faintness, or a shaky feeling upon rising. Blood pressure naturally reaches its lowest point during the second trimester (20 to 24 weeks), making this symptom most noticeable then.
The pregnant body also operates at a higher metabolic rate to fuel both the individual and the growing fetus. This increased demand for energy means the heart works harder, increasing cardiac output by as much as 50%. This higher workload can sometimes be felt as palpitations or an internal tremor, particularly when resting. Hormonal fluctuations, separate from blood pressure changes, can directly influence the nervous system, leading to an enhanced physiological tremor or the “labor shakes” that some people experience even before active labor begins.
Controllable Nutritional and Lifestyle Triggers
A frequent and easily addressed cause of shakiness is a dip in blood sugar (hypoglycemia). During pregnancy, the body’s insulin sensitivity increases, and the developing fetus continuously draws glucose from the maternal bloodstream. This leaves the pregnant individual vulnerable to low blood sugar if meals are delayed or insufficient. Symptoms like shaking, sweating, paleness, and a rapid heartbeat are the body’s adrenaline response to low blood glucose.
Inconsistent eating patterns or consuming meals high in simple sugars that cause a rapid spike and crash can worsen this instability. The body requires a steady supply of glucose, and going too long without food causes the release of stress hormones to mobilize energy reserves, which can trigger tremors. Eating small, frequent meals containing a balance of protein and complex carbohydrates helps maintain a more stable blood sugar curve.
Dehydration is another trigger that can mimic or exacerbate shakiness and lightheadedness. The increased fluid volume needed during pregnancy requires significantly more water, and inadequate intake quickly reduces overall blood volume. This lower volume can compound the effects of low blood pressure, causing weakness and dizziness. Insufficient sleep and elevated anxiety or stress also contribute, as fatigue lowers nervous system excitability and stress hormones induce physical shaking.
Warning Signs and Conditions Requiring a Doctor
While most instances of shakiness are benign, it is important to recognize when this symptom signals a more concerning underlying condition. Shakiness or dizziness that is severe, persistent, or does not resolve quickly after eating and resting should prompt medical consultation. The most serious warning signs occur when shakiness is accompanied by other specific symptoms.
Immediate medical consultation is necessary if shakiness is paired with a severe, non-resolving headache, blurred vision, or sudden, excessive swelling of the hands or face. These combinations of symptoms can indicate preeclampsia, a serious high blood pressure disorder that develops after 20 weeks of gestation. Shakiness accompanied by a persistent, rapid heart rate, chest pain, or shortness of breath could signal a cardiac issue or, less commonly, an underlying condition like hyperthyroidism.
Severe anemia, where a low red blood cell count impairs oxygen transport, is another condition to consider. This can lead to extreme fatigue, weakness, and dizziness, often perceived as internal shakiness. If vomiting is so severe that the pregnant person cannot keep down fluids for more than eight hours, the resulting severe dehydration can cause lightheadedness and weakness, indicating a need for treatment for hyperemesis gravidarum. Dizziness resulting in fainting or coupled with fever or chills should also be addressed immediately, as these may suggest infection or other urgent issues.
Immediate Relief and Prevention
For immediate relief from a bout of shakiness, the most effective action is to sit or lie down to improve blood flow to the brain. If the feeling is accompanied by hunger or sweating, it is likely due to low blood sugar, and a fast-acting source of glucose is recommended. Consuming about 15 grams of simple carbohydrates, such as half a cup of fruit juice or a small handful of glucose tablets, will quickly raise blood sugar.
Once the immediate symptoms subside, the rapid sugar intake should be followed by a snack containing protein and complex carbohydrates (e.g., cheese and crackers or fruit with peanut butter) to sustain the blood sugar level. To prevent future episodes, focus on consistent nutrition by eating small, balanced meals every three to four hours. Consistently drinking water, aiming for 8 to 10 glasses daily, helps maintain blood volume. Since low blood pressure often causes orthostatic symptoms, making slow, deliberate movements when changing positions can minimize dizziness. For example, pause at the edge of the bed before standing.