These conditions can be very common, and generally present with aches and pains and reduced ability to do activities as a result. The person may experience joints clicking/cracking or even popping in and out of their position (subluxation). If present for a long time they may affect the heart by producing funny heartbeat sensation and feeling faint on changing position (for example on standing up), and if ongoing this is called POTS (postural orthotstatic tachycardia syndrome).