You probably have hypothyroidism, low hemoglobin or you may be having a heart failure or even low blood pressure can cause such a problem Certain medicines and substances can lead to such a problem , including:     * Alcohol     * Anti-anxiety medicines     * Certain antidepressants     * Diuretics     * Heart medicines, including those used to treat high blood pressure and coronary heart disease     * Medicines used for surgery     * Painkillers Other causes  include:     * Nerve damage from diabetes     * Changes in heart rhythm (arrhythmias)     * Not drinking enough fluids (dehydration)     * Heart failure You can do a few things     * Drinking more fluids     * Getting up slowly after sitting or lying down     * Not drinking alcohol     * Not standing for a long time     * Using compression stockings so blood does not collect in the legs Get these test done to find cause tests include CBC, Thyroid functions, ECG , ECHO. HBA1c Watch these simple explanatory videos for understanding the problem. Copy the link address to your browser 1) Chest pain - must know https://youtu.be/xZunqXM3G1Y 2) Heart failure https://youtu.be/rgN3ez7CkHc https://youtu.be/j2LlMRwoX94 3) Three things to do in chest pain - https://youtu.be/v7glVnwnLDg 4) Difference between heart attack and heart blocks vs heart failure https://youtu.be/X5FDPT2bY3I Don't forget to share and subscribe the channel - Dr. EDUCATION. Please do share your feedback on the below link. Your opinion is valuable. http://prac.to/idax Regards Dr. PARAMJEET SINGH MBBS, DIP. CARDIOLOGY (LONDON), FICC. CONSULTANT CARDIOLOGIST YASHODA SUPERSPECIALITY HOSPITAL