The following are components of the Kundalini Energy System: Sushumna, Ida, Pingala (the 3 Nadis), and the Chakras (8 Chakras). So you can think of Kundalini Shakti as constituted by 2 components (nadis and chakras) or of 11 components (3 nadis plus 8 chakras); it really doesn't matter so long as you keep all in mind.
Awakening of these components is independent of each other. Whether you believe these components to be physiological or symbolic, please look at them in a mechanical manner. Consider them to be different parts of one big Kundalini Chakras system that interact with each via spiritual energy.
This perspective will also help you understand how physical exercises and even massage of the different chakra regions on the physical body can stimulate the chakras. Purifying and invoking the nadis is primary in this Kriya Yoga. The channels (nadis) that carry the prana are also the channels through which Kundalini Power will manifest itself.
Often, blocked chakras create a hindrance to the Kundalini process. This is due to the chaotic awakening of different components. Consider the following: observe our society today and you will see most of the advertising revolves around food and fashion. Almost all advertising makes use of sexual innuendos. Hence, we can only conclude that our society is stuck in the mooladhara chakra (muladhara chakra or root chakra) and the swadhisthana chakra (sacral chakra).
In contrast, think of those people who have no sex drive or do not have any interest in food and we will realize that they are revolving around other chakras. No one is superior or inferior to the other, it's simply a matter of identifying your current and dominating chakra.
The terms used here are 'purifying' and 'awakening' and this is done through special and specific asanas or a combination of them. There are also different types of chakra meditation that start rousing the dormant energy of Kundalini.
Tantra Yoga has for long maintained that a human being's potentialities can be stretched endlessly. Therefore, we needn't restrict ourselves to the commonly known 8 chakras. Our psychic ability enables us to move beyond manipura (navel chakra) to the anahata chakra (heart chakra or solar plexus chakra) to vishuddha chakra (throat chakra) and finally the crown chakra (sahasrara chakra). Along the way, we have the third eye chakra (ajna) and bindu which also need to be awakened so as to ensure the stability of the awakening.
When the central channel (sushumna nadi) is purified, there is a clear pathway for the ascent. If these initial steps have been taken, awakening of kundalini will only have positive effects. But if they have been neglected and Kundalini awakens, there will definitely be some negative results. Supposing you have awakened kundalini before sushumna awakening has taken place, then the shakti will not find a channel towards Shiva. It will remain obstructed in mooladhara chakra and will create tremendous sexual and neurotic problems. This is a negative result because you wanted to unite with Shiva but instead started experiencing the grosser things. And if the chakras are not awakened before Kundalini, the Shakti will get blocked in one of the chakras and remain stagnant.
Pingala conducts the life that is in your body and ida conducts the consciousness. These two nadis respectively feed the two hemispheres of the brain which in turn control every activity of the body. We ought to focus on discipline and not get too obsessed with the system. Ida and pingala function alternately and directly influence the temperature of the body, digestive and hormonal secretions, the brainwaves, and all the bodily systems. Ida and pingala function according to a natural cycle, but on account of poor eating habits and inharmonious lifestyles, the natural cycle is often disturbed. Sometimes one nadi predominates and the other is suppressed.
You will observe this when you look closely at your breath. Even if you don't have a cold (no nostrils are blocked), you will be breathing through only one nostril. When there is harmony between these two nadis sushumna is awakened. Thus, through the practices of Hatha Yoga, Pranayama, and Ashtanga Yoga, the nadis should be purified and disciplined. The best practice for this is actually nadi shodhana pranayama (where you breathe alternatively through each nostril).
Although most of us try to awaken mooladhara, swadhisthana, etc. it may not be necessary to awaken them because we may have evolved even beyond anahata on account of our good deeds (positive actions) or the great environment we live in. Consider an intellectually and spiritually thriving community that you may have been born in!
Anyways, all the chakras must be awakened before we make an attempt to awaken sushumna. If the chakras are not purified, then purification of the nadis will not serve any purpose. Every cell, tissue, or organ is directly related to one of the chakras. In this context, the systems traverse across the chakra regions. Therefore, the respiratory system is so important because breath control (pranayama) can also impact other systems like the circulatory system (oxygen-carrying blood).
Your whole body is connected with one or the other chakra. For example, the urinary, excretory, and reproductive systems are fed by swadhisthana chakra while the sexual organs are connected to the mooladhara chakra. The digestive system, small intestine, large intestine, and liver are all connected to manipura chakra. The heart and lungs are fed by anahata chakra.
The awakening of sushumna can also bring some mind exploding experiences which are sometimes very confusing. You may get a high fever or manifest the symptoms of some common disease or some baffling illness which medical experts find it difficult to analyze. At the time of sushumna awakening, the quality and experience of the mind begin to change. At this time, you also experience prophetic vision, but your visions or forewarnings may not be clear and you only foresee the bad things - imminent perils, accidents, and disasters.
It's in this context that most societies thrive on the five elements of Tantra: meat, fish, parched grain (considered to be an aphrodisiac), wine, and sex in everyday life. By focusing on an asana or mantra or meditation technique, one can stimulate specific chakras. The asanas are intended to create a mild awakening in the chakras which will ensure that you don't have any adverse experiences.
Everybody talks about the ascent of Kundalini, but few ever discuss the descent. When the descent of Kundalini occurs, it means the lower mental plane of the human being is no longer influenced by the mundane mind, the supermind takes over instead. This higher form of consciousness rules the body, mind, and senses and directs your life, thoughts, and emotions. Kundalini becomes the ruler of your life. Not surprisingly, we can see this in sophisticated cultures where unbridled sex is not practiced and there isn't a single counterpart of a Jerry Springer show!
Shiva and Shakti unite in sahasrara to bring about illumination or enlightenment.
But what is this enlightenment?
Think of it simply as throwing light on each and every aspect of your personality. You will see that all morality is a product of society (the society you live in) and all righteousness is based on what kind of justice system you have subscribed to. As educated, civilized beings all our actions are controlled by our upbringing - based on what we 'believe' to be right or 'believe' to be wrong! Illumination is the correct word here: you will see that all constructs are artificial: love descends to being another "feeling" and God becomes just another delusion. With this emptiness comes the ultimate realization that life and existence itself are meaningless. It is for us to give Life a meaning!
This also brings with it immense power: Imagine feeling greater than God; comprehending that the universe is a vast empty space but you provide it creativity; or giving a sunrise or the northern lights their awe-inspiring beauty.
The infinity of space-time is nothing if there's no one to articulate it. Shakti gives the world its beauty and Shiva provides the conscious space within which everything must exist. When you start dancing between these two thoughts you are being Shakti and Shiva alternately and in that communion, you become the supreme non-dual self!
This is not a state of megalomania! This is a state of becoming one with the universe!
This is samadhi!
So don't be misled by any information which states that samadhi is attained only when you die. Shiva and Shakti merge for a while then separate and then merge again. Oscillating at this level - or experiencing this mental state - is what Kundalini awakening is all about. Having reached this sate, with complete and lasting awakening, it does not matter if you go back to your normal life. You will go back to being a father/mother, husband/wife, employee/boss... it doesn't matter because it will have a profound meaning.
Presently, two books come to mind - both describe Human History in a profound manner: Descent of Man (Charles Darwin) and Ascent of Man (Jacob Bronowski). I confess it's a play on words, but both provide an amazing perspective on how humans came to be and how we can aspire to be.
Before awakening, Kundalini can ascend and descend in a gross manner but when awakening has taken place you can traverse any mental state without worry. Having conquered something, you live the rest of your life exulting in your victory. You go back to be a child but with immense insights and knowledge.
That is why the self-realized man is able to understand the pain and all the mundane affairs of life. He understands the whole drama of duality, multiplicity, and diversity. Sometimes we ordinary mortals are at a fix to understand how this man with the highest attainment is able to cope with the hopeless mundanities of life. But then for him, these things are not mundane anymore!
When the actual awakening of Kundalini takes place, it is a great event in man's life. The awakening of kundalini has tangible, positive, and concrete proofs. You cannot believe your Kundalini is awakened if you have no proof because when the awakening of Kundalini takes place, you completely transcend the normal categories of mental awareness and the scope of your knowledge becomes greater.